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Information Technology Management
INFORMATICS
Unit 15: Decision Support System and Executive Information System
Information Technology Management
Lecture 7
17th July 2006 ITM Lecture 7 Advanced Diploma (Thames College)
ITM Lecture 7 Advanced Diploma (Thames College)
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Decision Support System (DSS)
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What is a Decision Support System? An organized collection of people, procedures, software, database, and devices used to support problem-specific decision making z An interactive, highly "user-friendly" system that supports management decisions that are semistructured or that cannot be specified in advance z Focus on decision-making effectiveness z Offers the potential to generate higher profits, lower costs and better products and services z
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DSS & Decision Making Level z z z
Components of DSS
Decision Support System, though skewed towards top level management, are used at all levels Managers at all levels face unstructured decisions Quantity and magnitude of unstructured decisions increases with management level
ITM Lecture 7 Advanced Diploma (Thames College)
zA
Decision Support System is composed of the following: z User
Interface z Data Management z Model Management
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Components of DSS – User Interface
Components of DSS – Data Management
z Users
zA
interact with a DSS through the user interface. z It is important therefore that user interfaces are easy to learn and to use. z The method of interfacing may vary with each DSS.
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typical DSS will access more than one database. These may contain both internal and external data. z Data is extracted from these databases and updated into a DSS database.
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Components of DSS – Model Management
Business Applications
z The
z
Model Management subsystem contains the model base. z Models are software programs that support the user in a particular decision making situation.
Financial Investment z
z
z
Ship Loading and Unloading z
ITM Lecture 7 Advanced Diploma (Thames College)
Some investment banks and brokerage firms use DSS in taking market positions with their own assets. The decision-making support comes in the form of the software's ability to identify trends or disturbances in the market prices of securities and options. DSS can be used to load and unload ships in an optimal fashion. This is important as a ship could be picking up and dropping off cargo at many different ports.
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Benefits
Benefits (1)
z Fast
z Fast
Response to Unexpected Situations z New Insights and Learning z Cost Savings
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Response to Unexpected Situations
zA
DSS enables a thorough, quantitative analysis in a short time. z This results in the user being able to handle rapid changes in business situations without waiting for the IT department to perform programming changes as would be the case in an IRS. 11
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Benefits (2)
Benefits (3)
z New
z Cost
Insights and Learning
z The
user can be exposed to new insights throughout the composition of the model and an extensive sensitivity "what-is" analysis. z The new insights can help in training inexperienced managers and other employees as well. ITM Lecture 7 Advanced Diploma (Thames College)
z Routine
applications of a DSS may result in consideration cost reduction, or in reducing the cost of wrong decisions.
z z
Group Decision Support System (GDSS) is a decision support system which provides support for problem formulation and solution and decision making by groups or teams of people GDSS is designed to support effective group communication and good decision making techniques, as well as creative thinking. GDSS software must be especially user friendly, since often groups have less patience with bad software than do individuals. ITM Lecture 7 Advanced Diploma (Thames College)
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Group Decision Support System (GDSS) z
Savings
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Components of the GDSS z There
are five components in GDSS
z Hardware z Software z People z Data z Procedures
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Characteristics of a GDSS z
Decision-making support z
z z
z
z
z Lotus
Delphi approach: Decision makers are scattered around the globe Brainstorming: Say things as you think (think out loud) Group consensus approach: The group reaches a unanimous decision (everybody agrees) Nominal group technique: Voting
Notes
z Store,
manipulate, distribute memos
z Microsoft
Exchange
z Keep
individual schedules z Decide on meeting times
Reduction of negative group behavior z
z
Examples of GDSS Software
A trained meeting facilitator to help with sidetracking
Automated record keeping ITM Lecture 7 Advanced Diploma (Thames College)
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Executive Information Systems
Executive Information System (EIS)
z
z
z z
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An Executive Information Systems (EIS) is a system that serves the information needs of top executives by providing rapid access to timely information with "drill-down" capabilities. It is intended that the senior executive has the latest details about the company's key performance indicators as well as economic and industrial indicators. These are information that a top executive requires to monitor the health of a large organization. The information presented through an EIS come from both internal and databases and external sources like the online Dow Jones News Retrieval service. ITM Lecture 7 Advanced Diploma (Thames College)
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Executive Problem Analysis z z z
z z
Information Technology Management
Having identified a significant variance, the executive needs to view the data from a number of different perspectives. It is not enough to know that an unfavorable profit variance of 10% has occurred in one of the subsidiaries. Some divisions within that subsidiary may have increased profits while other divisions have deviations of more than 10%. An EIS can support multiple levels of investigation. By selecting the highlighted variance on the screen, it is possible to obtain more details of causes, "drilling-down" to get lower levels of details. ITM Lecture 7 Advanced Diploma (Thames College)
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Relevance of Information to Management Decisions
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What is an MIS?
Managers are not able to directly observe all aspects of operations and therefore depend on information in the form of reports to help them. z Management are faced by an accelerating rate of change, an ever more complex environment and at higher levels, by considerable uncertainty. z It is difficulty to produce relevant information but ironically, it is even more important to managers today. z
ITM Lecture 7 Advanced Diploma (Thames College)
Unit 16: Strategic Role of Information Systems
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z To
convert data from internal & external sources into information z To communicate this information to managers z To enable them to make timely and effective decisions z Emphasis on the use of information, not on how it is produced. ITM Lecture 7 Advanced Diploma (Thames College)
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Definition of MIS?
MIS and IT
z The
definition of a Management Information System is: z
z
A system to convert data from internal and external sources into information and to communicate this information, in an appropriate form, to managers at all levels in all functions to enable them to make timely and effective decisions for planning, directing and controlling the activities for which they are responsible. ITM Lecture 7 Advanced Diploma (Thames College)
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Strategic Management
Management is often divided into three levels based on the type of management activity performed. z Strategic Management z Tactical Management z Operational Management
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z
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Management Levels z
z
An MIS in today's context is usually a mixture, with the computer being used for storage and processing of data, while the human processes come into play when judgment is called for, or when an unusual situation arises. Information technology is not essential to an MIS but it can be very useful. At higher levels of management, there is a greater amount of unstructured problems and decisions where human involvement is essential.
z Strategic
management deals with long range considerations. z Decisions to be made deal with the choice of business direction, market strategy, product mix, etc.
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Tactical Management
Operational Management
z Tactical
management has a medium term planning horizon. z It includes acquisition and organization of resources, structuring of work, and recruiting and training of personnel. ITM Lecture 7 Advanced Diploma (Thames College)
z Operational
management is related to short term decisions for current operations. z Pricing, production levels, inventory levels, etc, are the result of operational planning and control.
MIS for Operational Management z At
the operational management level, the main concern is with the implementation and control of the day-to-day activities of the organization. z Operational management require their MIS to provide them detailed control information about transactions. ITM Lecture 7 Advanced Diploma (Thames College)
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MIS for Tactical Management Tactical level management implement strategic objectives and monitor operations. z Unlike MIS at the operational level, there is no best design for tactical level MIS. z In many cases, the MIS for tactical management is part of a transaction processing system. z Control systems with information feedback are essential to carry out the monitoring role and it is this level which administers most of the well known conventional control systems such as budgetary control, production control, inventory control and so on. z
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MIS for Strategic Management
Problems with MIS
Strategic planning and decision making involves setting a long term direction for the company. z Strategic management needs to understand the environment and predict key trends and challenges facing the organization in the future. z There is a need for MIS to obtain information about the environment by a scanning and information gathering process in order to identify potential threats and opportunities. z
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MIS cannot provide management with the information they need due to the following reasons: z z z z z z
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Competitive Forces
Strategic Role of Information Systems z Information
systems are no longer restricted to backroom support roles. z Organizations are increasingly aware of the potential strategic applications of information systems.
Michael Porter discussed 5 organization-level competitive forces in an industry which together determine how strong an organization is in its industry. z These forces are: z
z z z z z
ITM Lecture 7 Advanced Diploma (Thames College)
Lack of Management Direction Lack of management knowledge of computers Lack of top management support Lack of management participation in MIS design Management do not always know what information they need IT personnel often do not know enough about management to produce relevant information for the managers they serve
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Bargaining Power of Suppliers Bargaining Power of Buyers Threats of New Entrants Threats of Substitution Intensity of Rivalry ITM Lecture 7 Advanced Diploma (Thames College)
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Bargaining Power of Suppliers
Bargaining Power of Buyers
The bargaining power of suppliers is high if there are concentrated sources of supply and few substitutes. z If these near monopoly situations, the suppliers can push prices upward and can be indifferent about service or quality. z Information Technology can be used to reduce supplier power by developing in-house capability to produce or service or buying into a supplier. z
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z
z
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Threats of Substitution
When an industry experiences good profit margins, it is attractive for new entrants to join the industry and this will create downward pressure on prices due to the increased availability of products and service. An existing player in the market can create can entry barrier by using IT to make the cost too high for any new player. A new entrant can use IT to improve its services or product and thereby, overcome barriers set up by existing players. ITM Lecture 7 Advanced Diploma (Thames College)
buyer is high (e.g. when the buyer is large and/or the products are undifferentiated), then there is downward pressure on prices and upward pressure on both product quality and service. z Information Technology can be used to reduce buyer power such as increasing switching costs.
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Threats of New Entrants z
z When
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z Substitution
of products and services can reduce or eliminate the market for existing organizations and thereby weaken it. z A late entrant to the market may choose to introduce a product that is a technological advancement over the existing products in the market, and thereby weaken existing players by the threat of substitution. ITM Lecture 7 Advanced Diploma (Thames College)
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Intensity of Rivalry
Competitive Strategy
z The
intensity of rivalry in the market affects the overall profitability, and it is usually greater in mature or declining markets. z Price wars usually benefit the consumer and eliminate some of the weaker players in the market. z IT can be used to overcome the dilemma of having to lower prices while increasing levels of service. ITM Lecture 7 Advanced Diploma (Thames College)
z
Firms have discovered many different approaches and the best strategy for a given firm is ultimately a unique combination reflecting its particular circumstances. At the broadest level we can identify three internally consistent generic strategies for creating such a defendable position in the long and outperforming competitors in an industry: z z z
Overall Cost Leadership Differentiation Focus ITM Lecture 7 Advanced Diploma (Thames College)
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Competitive Strategy – Overall Cost Leadership
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Competitive Strategy Differentiation
Cost leadership exists when a company can provide an "identical" product or service at the lowest cost in that industry. z Cost leadership requires aggressive construction of efficient - scale facilities, vigorous pursuit of cost reductions from experience, tight cost and overhead control, avoidance of marginal customer accounts, and cost minimization in areas like R&D service, sales force, advertising, and so on. z A great deal of managerial attention to cost control is necessary to achieve these aims. z
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z
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z An
organization may choose to provide a differentiated Unique product or service at a premium price in that industry. z The aim in differentiating the product or service offering of the term is to create something that is perceived industry-wide as being unique. ITM Lecture 7 Advanced Diploma (Thames College)
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Competitive Strategy - Focus z
z
z z
Information Technology Management
Focus its product or service provision on a particular buyer group, segment of the product line, or geographic market for an identified market segment, by either cost leadership or differentiation. The entire focus strategy is built around serving a particular target very well, and each functional policy is developed with this in mind. Able to serve its narrow strategic target more effectively or efficiently than competitors who are competing more broadly. Achieves either differentiation from better meeting the needs of the particular target, or lower costs in serving this target, or both. ITM Lecture 7 Advanced Diploma (Thames College)
Unit 17: Prototyping and Feasibility Study
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Problems with Classical SDLC
Prototyping and Feasibility Study
z User
Requirements Change z Incomplete User Requirements z Development Targets are Missed
Prototyping
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Problems with Classical SDLC User Requirements Change z z z z
Problems with Classical SDLC Incomplete User Requirements
Systems often take years to analyze, design, and implement. During development period, the environment and user needs is are constantly changing. The finished system might not meet the new applications environment. With the traditional SLDC approach, it is relatively difficult to respond to new needs once users have signed off on the requirements analysis and the design. ITM Lecture 7 Advanced Diploma (Thames College)
z z z z
z z
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Prototyping
Systems developers are often notoriously optimistic. Deadlines are set and missed; then re-set and often missed again. The systems usually require more resources than originally estimated and costs frequently climb over budget. Problems of miscommunication, omissions, and human error complicate matters. Projects are often cancelled as cost begin to exceed benefits and the probability of ever finishing them within a reasonable span of time becomes more and more remote. ITM Lecture 7 Advanced Diploma (Thames College)
z
People often cannot articulate what type of information they really need in their work. With the traditional SDLC approach, users do not really see the new system until it is installed. Many users have a difficult time visualizing the system by looking at a set of diagrams or specifications. Requirements analysis had to be repeated because additional requirements were discovered or because users changed their minds.
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Problems with Classical SDLC Development Targets are Missed z
z
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z The
process of building an experimental system quickly and inexpensively for demonstration and evaluation so that users can better determine information requirements. z By interacting with the prototype, users can get a better idea of their information requirements ITM Lecture 7 Advanced Diploma (Thames College)
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Phase 1: Define System Specifications
The Prototyping Process z Phase z
2: 3:
Refine the Prototype System.
z Phase z
of the rough spots in the prespecification approach to systems development has been the definition of system specifications.
Creating the Prototype System.
z Phase z
z One
Define System Specifications.
z Phase z
1:
4:
Develop Operational System. ITM Lecture 7 Advanced Diploma (Thames College)
Phase 2: Creating the Prototype System
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Phase 3: Refine the Prototype System
z Project
team members rough out the logic of the system and how the elements fit together and then work with the user to define the I/O interfaces.
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z Users
sit down at a terminal or PC and evaluate portions and eventually all of the prototype system. z The system is then expanded and refined to meet the users' total information needs.
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Phase 4: Develop Operational System z The
System Prototyping z Prototyping
involves a repetitive sequence of analysis, design, modeling and testing. z The end product of System Prototyping is a full-featured, working model of the information system, ready for implementation.
prototype system is custom coded.
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Design Prototyping
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Advantages of Prototyping
Design Prototyping is used to verify user requirements. z The end product of Design Prototyping is a userapproved design prototype that documents and benchmarks the features of the finished system. z
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z Most
useful when there is uncertainty about requirements or design solutions. z Valuable for the design of End-user interface of an Information System. z Prototyping encourages intense end-user involvement throughout the systems development lifecycle. z It is more likely to produce systems that fulfill user requirements. ITM Lecture 7 Advanced Diploma (Thames College)
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Disadvantages of Prototyping
Prototyping and Feasibility Study
z The
rapid pace of development can create quality problems, which are not discovered until the finished system is operational. z Other system requirements, such as reliability and maintainability, cannot adequately be tested using a prototype. z In very complex systems, the prototype becomes unwieldy and difficult to manage ITM Lecture 7 Advanced Diploma (Thames College)
z z
z
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Types of Feasibility
The Feasibility Study is one of the steps within the Preliminary Investigation Phase of the Systems Development Life Cycle (SLDC). The analyst learns from the user what is expected of the proposed information system. The analyst uses technical skills and knowledge to decide on various alternatives to be considered for implementation. The feasibility study has to contain enough detail so that an alternative can be selected for development. ITM Lecture 7 Advanced Diploma (Thames College)
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What is a Feasibility Study? z
Feasibility Study
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Different types of feasibility that must be evaluated in order to determine if the project is worth doing. z A feasibility study uses three major yardsticks to measure, or predict a system's success: z
z z z
Economic Feasibility Technical Feasibility Operational Feasibility
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Operational Feasibility
Technical Feasibility
zA
system that has operational feasibility is one that will be used effectively after it has been developed.
A systems request has technical feasibility if the organization has the resources to develop or purchase, install, and operate the system. z Project risk can be assessed based upon: z
z z z
z
ITM Lecture 7 Advanced Diploma (Thames College)
Project size Project structure Development group's experience with the application User group's experience with development projects and the application area ITM Lecture 7 Advanced Diploma (Thames College)
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Economic Feasibility
What is Costs?
A systems request has economic feasibility if the projected benefits of the proposed system outweigh the estimated costs involved in acquiring, installing, and operating it. z Before management will approve any large computer system, an appraisal of the benefits and costs of the system must be done. z Essentially what happens is that all costs associated with the proposed systems project is calculated, as well as the benefits to be derived from this system. z Then we use certain financial methods to rank projects. z
z
Among the cost items that are taken into consideration are hardware, software, personnel, and establishment of new procedures and representations of data. z Cost is divided into several types: z
Tangible Costs (can easily be measured in dollars) z
z
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Example: Hardware
Intangible Costs (cannot be easily measured in dollars) z
Examples: loss of customer goodwill, loss of employee morale
z
One-Time Costs (project startup, initiation and development)
z
Recurring Costs (ongoing use of the system)
z
z ITM Lecture 7 Advanced Diploma (Thames College)
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Example: System Development, Data Conversion Example: Software Maintenance ITM Lecture 7 Advanced Diploma (Thames College)
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What is Benefits? z
What is Requirement?
The benefits are divided into Tangible Benefits and Intangible Benefits. z
Requirement is a feature that users identify as being necessary or useful in a system. z How are requirements determined?
Tangible Benefits are those that can be measured easily (most readily translated into dollars). z
z
zA
The business must first be understood. z The problems are studied and opportunities for improvement are identified. z It is these opportunities that are eventually turned into statements of requirements.
Examples: Cost reduction, Opening new markets and increasing sales opportunities
z
Intangible Benefits are those that cannot be measured easily (difficult to quantify) z
Examples: Increased employee morale, Promotion of organizational learning and understanding ITM Lecture 7 Advanced Diploma (Thames College)
Importance of Requirements z z z z z
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Methods of Data Collection
The requirements stage is one of the early stages in SDLC. By studying both the existing and proposed systems in detail, various problems can be anticipated. It is important to consider how these problems can be solved or at least, how to minimize their impact. It is important that requirements are clear and complete. Subtle misunderstandings may result in defects which could be hard to detect. ITM Lecture 7 Advanced Diploma (Thames College)
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z Primary
data collection involves direct interaction with the source of the data. z Interview z Observation z Questionnaire z Documents
Review
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Interview z z z z
z
Observation
The systems analyst spends a great deal of time interacting with others, particular in interviews settings. Interviews have varying degrees of structure; for a first meeting there may be no structure at all. As the project progresses, more structured interviews are conducted. The analyst may wish to prepare in advance an interview schedule containing the questions to be asked and the pints to be covered. This will ensure that no pint is omitted or that the interview drifts from its original objectives. ITM Lecture 7 Advanced Diploma (Thames College)
technique for collecting data on a process is to observe that process. z Frequently in systems analysis and design we will Walkthrough system observing crucial information flows and decision points.
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Questionnaire
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Documents Review
zA
questionnaire allows us to collect data from a relatively large number of people at a reasonable cost. z A questionnaire can be thought of as a structured interview form with questions designed so that they can be answered without face-to-face encounter. z Designing a good questionnaire is a difficult task. ITM Lecture 7 Advanced Diploma (Thames College)
z One
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z Some
types of information may be obtained from reviewing existing company records or documents. z The existing work procedures or company policy may be reviewed to obtain information about the current business processes. z An examination may be made of company records concerning the volume of invoices or shipment to determine problem areas. ITM Lecture 7 Advanced Diploma (Thames College)
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Data Flow Diagrams (DFD)
Problems of Conventional Flowcharts
zA
Data Flow Diagram (DFD) is a graphical tool to depict the flow of data through a system and the work or processing performed by that system.
z Lack
of discipline or structure. z Very few guidelines on how to develop flowcharts z Flowcharts for complex systems are often unreadable. ITM Lecture 7 Advanced Diploma (Thames College)
It shows how data moves through an information system but does not show program logic or processing steps. z It only represent a logical model that shows what the system does, not how it does it. z
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Data Flow Diagrams z
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DFD Symbols/Elements
Data Flow Diagrams (DFD) require only four symbols, making them very easy to create. z
z z z
z
ITM Lecture 7 Advanced Diploma (Thames College)
Open-ended rectangles represent store of data, such as a file of items in inventory, their quantity, and the Economic Recorder Quantity ( EOQ). Circles stand for some type of processing, and arrows represent the flow of data. A square is a source or destination of data. Dataflow diagrams should also be prepared in a topdown manner.
The context diagram is a summary diagram of the first level DFD and serves to put the system under study in its context within the business environment. ITM Lecture 7 Advanced Diploma (Thames College)
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Data Flow Diagrams (DFD)
Decomposition of Context Diagram
z Tool
that graphically shows flow of data in system
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Context Diagrams
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Level 1 Diagrams
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Entity Diagrams
Entity-Relationship Diagram (ERD)
z
z Tool
that graphically shows connections between entities in system
z z z
z z
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Systems Implementation and Development Tools
Information Technology Management
Unit 18: Systems Implementation and Development Tools
ITM Lecture 7 Advanced Diploma (Thames College)
An entity is an item of interest to the organization like a department, staff, machines, customers, etc. An entity diagram shows the relationships between such items of interest. Take the example of a department and its staff, both of which are entities. The relationship between these entities can be shown by drawing a diagram linking them together. We could also show a particular kind of relationship like one to many. The entity diagram can be used to understand and communicate the relationships between entities. The data fields (attributes) associated with each entity may also be documented.
Conversion
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Conversion Tasks z
z
z
z
Data Conversion Methods
To ensure a smooth and successful implementation, users must be familiar with the features of the system, operators must know how to make the system function properly, and the conversion itself must go off smoothly. Conversion includes the creation of all required files and database, establishing a backup copies, and converting tested programs to operating status. Data conversion is a central part of a system conversion regardless whether the preceding system was manual or computer-based. The data conversion must be carefully planned and also crosschecked to see that it is done right. ITM Lecture 7 Advanced Diploma (Thames College)
are fours strategies, the choice of which is dictated by the given situation z Parallel
Systems z Direct Cutover z Pilot System z Phase-in of System
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Data Conversion Methods – Parallel Systems
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Data Conversion Methods – Direct Cutover
A safe and conservative conversion approach z Running both old and new systems for a period of time z The output of the new system is compared closely with the output of the old system and any difference reconciled z When users are comfortable that the new system is working properly, the old system is eliminated z Very expensive, additional staff is required. z
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z There
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z
z z z
This method of conversion require much more careful and detailed planning than the other alternatives. A risky conversion approach in which the new system completely replaces the old one on an appointed day. Involves stopping the old system and starting the new system on a specific date. High potential for problems and errors. Less costly if no problem, otherwise more costly. ITM Lecture 7 Advanced Diploma (Thames College)
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Data Conversion Methods – Pilot System
Data Conversion Methods Phase-in of System
z Involves
running the new system for one group of uses rather than all users z When the pilot system runs without problems then it is rolled out to the other users
z z
z
z
ITM Lecture 7 Advanced Diploma (Thames College)
Piecemeal approach Components of the new system are slowly phased in while components of the old system are slowly phased out Allows the organization to being taking advantage of the newly developed support tools while retaining flexibility to cope with any deficiencies When everyone is confident that the new system is performing as expected, then the old system is completely phased out ITM Lecture 7 Advanced Diploma (Thames College)
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Systems Implementation and Development Tools
94
Classroom Training z Classroom
training involves a live instructor conducting training for students.
Training
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Advantages z
Disadvantages
Classroom training has several strong advantages over other forms of training, which do not use live instructors. z z
z
z
z
z
Feedback is immediate when the problems occur. Both the Learners and the teachers can ask questions to gauge the group's understanding. The teaching can be tailored to the learners by adding company-specific examples or job-specific examples. The classroom is a familiar and acceptable environment for most people.
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z
z
z
It is usually more expensive than mediated training without instructors. Training facilities are expensive, particular, if hands-on computer training is to be done. Users have to wait until a class starts to get the training they need. Teaching quality can vary considerably from course to course.
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Internal vs. External Training
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Advantages of Internal Training
z If
the company decides to sponsor training, the next step is to decide whether to do it internally or whether to contract the training out to external vendors.
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On the negative side, classroom instruction also has a number of strong disadvantages.
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z Many
firms use internal training because it has several important advantages. There is greater control over quality. If there are quality problems, these can be overcome. With external training, there is less control over quality. z Courses can be tailored to the corporation by including company-specific information. z
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Advantages of External Training z
Summary
External vendors offer a number of advantages over internal training. z
z z
If internal training is done in geographically decentralized organizations, the use of external vendors can provide cheaper local training when popular application software packages or the basic use of the computer are to be taught. Unless a firm has a very large training program, external training will be less expensive. For popular software packages or basic machine use, external vendors will offer courses almost continuously, whereas internal programs may offer these course less frequently. ITM Lecture 7 Advanced Diploma (Thames College)
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Systems Implementation and Development Tools
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Development Tools Computer Aided Software Engineering (CASE) is the use of computer technology to help improve application systems development. z The earliest CASE tools were used to create flowcharts and data flow diagrams. z Later versions of CASE allowed computer professionals to create complete and detailed specifications and to later generate structured program code. z The CASE software can then generate a detailed documentation package for easy maintenance. z
Development Tools
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Features of CASE – Draw Descriptive Diagrams
Features of CASE z CASE
consists of a set of workstationbased software tools designed to support application developers. z The activities that most CASE tools include are described below. z Draw
Descriptive Diagrams z Maintain Data Dictionary z Design Display Screens z Design Output Layouts ITM Lecture 7 Advanced Diploma (Thames College)
tools provide the developer with the ability to draw various types of diagrams like data flow diagram, flowcharts, etc.
z Making
modifications to diagrams is much faster with this tool. ITM Lecture 7 Advanced Diploma (Thames College)
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Features of CASE – Maintain Data Dictionary
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Features of CASE – Design Display Screens
z This
is used to store and validate definitions of data items used in the system.
z It
also records the programs or tables where each data item is used.
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z Diagramming
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z CASE
is used to quickly create screen designs and to generate the code based on this design. z These can be reused in other applications. z Screen intensity, use of reverse letters and inclusion of underlining are all easily specified. ITM Lecture 7 Advanced Diploma (Thames College)
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Features of CASE – Design Output Layouts
Benefits of CASE z What
z As
with screen designs, CASE tools can also be used to design report layouts.
z Development
time is shortened z Development standards can be enforced. z Data Dictionary is automatically produced
z Consistency
between reports can be achieved by starting with one standard template.
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are the benefits of using CASE?
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Benefits of CASE – Development Time is Shortened
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Benefits of CASE – Development Standards can be Enforced
z With
automated tools, the effort required to complete each task is lessened.
z Standards
z For
example, instead of drawing data flow diagrams by hand, it can be done with CASE.
define the rules for certain development decisions. z Having these standards embedded in software ensures it is more consistently performed. z For
example, an organization may have standards regarding the naming convention of data fields or the diagramming method.
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Benefits of CASE – Data Dictionary is Automatically Produced
Limitations of CASE
z There
is no need to review the entire system to ensure that the data dictionary is complete and consistent if each data field is defined in the data dictionary at its point of creation.
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software is not able to support the full development life cycle. z The design to code transformation is not fully automated, and results in much analyst and the programmer effort anyway.
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User Documentation
are two types of documentation
z
z User
Documentation z Operations Documentation
z
z z
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not support the full SDLC
z CASE
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Documentation z There
z Does
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The first type of documentation is the User Manual, also known as the User Guide. The user manual contains screen and report layouts, with explanation of how to use a transaction, or read a report. It also has other features like a list of error conditions and how to correct error. The user manual should be referred to by the user who has a question or a problem about the system before he or she refers to the IT person supporting the application. ITM Lecture 7 Advanced Diploma (Thames College)
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Operations Documentation z z z
z
z
Importance of Documentation
The operations section of an IT department has to operate the system after it has been implemented. This group needs information on normal operating procedures and on how to respond to errors. The Operations Manual will contain information about starting and shutting down the system, plus details about how to run the batch jobs. For each batch job, a complete systems flowchart that shows the input required, the files necessary, and any printed output must be documented. It is important for operators to know possible error conditions and how to respond to them. ITM Lecture 7 Advanced Diploma (Thames College)
particularly so if there is a deadline approaching and if the tasks are behind schedule. z Documentation must be treated as part of the complete package of deliverables. z Why is documentation important ? z Manage
the Project z Obtain Consensus ITM Lecture 7 Advanced Diploma (Thames College)
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Manage the Project
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Obtain Consensus
z Documentation
is a tool used to manage the development process. This is done in a few ways. z It
is used to review tasks which have been completed or which are going to be done. z It is used to monitor progress and take corrective action. z It is used to make decisions on future tasks. z It is the tools used to manage the development process, to control its activities and plan future steps. ITM Lecture 7 Advanced Diploma (Thames College)
z This
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z In
any complex task involving many parties, there is always a possibility of misunderstanding. z The agreement should be documented and a copy sent to all parties involved for feedback and agreement. While this does not guarantee that there will not be any miscommunication, it does minimize it. ITM Lecture 7 Advanced Diploma (Thames College)
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Questions & Discussion
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INFORMATICS
Unit 15: Decision Support System and Executive Information System
Information Technology Management
Lecture 7
17th July 2006 ITM Lecture 7 Advanced Diploma (Thames College)
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Decision Support System (DSS)
2
What is a Decision Support System? An organized collection of people, procedures, software, database, and devices used to support problem-specific decision making z An interactive, highly "user-friendly" system that supports management decisions that are semistructured or that cannot be specified in advance z Focus on decision-making effectiveness z Offers the potential to generate higher profits, lower costs and better products and services z
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DSS & Decision Making Level z z z
Components of DSS
Decision Support System, though skewed towards top level management, are used at all levels Managers at all levels face unstructured decisions Quantity and magnitude of unstructured decisions increases with management level
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zA
Decision Support System is composed of the following: z User
Interface z Data Management z Model Management
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Components of DSS – User Interface
Components of DSS – Data Management
z Users
zA
interact with a DSS through the user interface. z It is important therefore that user interfaces are easy to learn and to use. z The method of interfacing may vary with each DSS.
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typical DSS will access more than one database. These may contain both internal and external data. z Data is extracted from these databases and updated into a DSS database.
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Components of DSS – Model Management
Business Applications
z The
z
Model Management subsystem contains the model base. z Models are software programs that support the user in a particular decision making situation.
Financial Investment z
z
z
Ship Loading and Unloading z
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Some investment banks and brokerage firms use DSS in taking market positions with their own assets. The decision-making support comes in the form of the software's ability to identify trends or disturbances in the market prices of securities and options. DSS can be used to load and unload ships in an optimal fashion. This is important as a ship could be picking up and dropping off cargo at many different ports.
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Benefits
Benefits (1)
z Fast
z Fast
Response to Unexpected Situations z New Insights and Learning z Cost Savings
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Response to Unexpected Situations
zA
DSS enables a thorough, quantitative analysis in a short time. z This results in the user being able to handle rapid changes in business situations without waiting for the IT department to perform programming changes as would be the case in an IRS. 11
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Benefits (2)
Benefits (3)
z New
z Cost
Insights and Learning
z The
user can be exposed to new insights throughout the composition of the model and an extensive sensitivity "what-is" analysis. z The new insights can help in training inexperienced managers and other employees as well. ITM Lecture 7 Advanced Diploma (Thames College)
z Routine
applications of a DSS may result in consideration cost reduction, or in reducing the cost of wrong decisions.
z z
Group Decision Support System (GDSS) is a decision support system which provides support for problem formulation and solution and decision making by groups or teams of people GDSS is designed to support effective group communication and good decision making techniques, as well as creative thinking. GDSS software must be especially user friendly, since often groups have less patience with bad software than do individuals. ITM Lecture 7 Advanced Diploma (Thames College)
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Group Decision Support System (GDSS) z
Savings
14
Components of the GDSS z There
are five components in GDSS
z Hardware z Software z People z Data z Procedures
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Characteristics of a GDSS z
Decision-making support z
z z
z
z
z Lotus
Delphi approach: Decision makers are scattered around the globe Brainstorming: Say things as you think (think out loud) Group consensus approach: The group reaches a unanimous decision (everybody agrees) Nominal group technique: Voting
Notes
z Store,
manipulate, distribute memos
z Microsoft
Exchange
z Keep
individual schedules z Decide on meeting times
Reduction of negative group behavior z
z
Examples of GDSS Software
A trained meeting facilitator to help with sidetracking
Automated record keeping ITM Lecture 7 Advanced Diploma (Thames College)
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Executive Information Systems
Executive Information System (EIS)
z
z
z z
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An Executive Information Systems (EIS) is a system that serves the information needs of top executives by providing rapid access to timely information with "drill-down" capabilities. It is intended that the senior executive has the latest details about the company's key performance indicators as well as economic and industrial indicators. These are information that a top executive requires to monitor the health of a large organization. The information presented through an EIS come from both internal and databases and external sources like the online Dow Jones News Retrieval service. ITM Lecture 7 Advanced Diploma (Thames College)
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Executive Problem Analysis z z z
z z
Information Technology Management
Having identified a significant variance, the executive needs to view the data from a number of different perspectives. It is not enough to know that an unfavorable profit variance of 10% has occurred in one of the subsidiaries. Some divisions within that subsidiary may have increased profits while other divisions have deviations of more than 10%. An EIS can support multiple levels of investigation. By selecting the highlighted variance on the screen, it is possible to obtain more details of causes, "drilling-down" to get lower levels of details. ITM Lecture 7 Advanced Diploma (Thames College)
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Relevance of Information to Management Decisions
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What is an MIS?
Managers are not able to directly observe all aspects of operations and therefore depend on information in the form of reports to help them. z Management are faced by an accelerating rate of change, an ever more complex environment and at higher levels, by considerable uncertainty. z It is difficulty to produce relevant information but ironically, it is even more important to managers today. z
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Unit 16: Strategic Role of Information Systems
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z To
convert data from internal & external sources into information z To communicate this information to managers z To enable them to make timely and effective decisions z Emphasis on the use of information, not on how it is produced. ITM Lecture 7 Advanced Diploma (Thames College)
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Definition of MIS?
MIS and IT
z The
definition of a Management Information System is: z
z
A system to convert data from internal and external sources into information and to communicate this information, in an appropriate form, to managers at all levels in all functions to enable them to make timely and effective decisions for planning, directing and controlling the activities for which they are responsible. ITM Lecture 7 Advanced Diploma (Thames College)
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Strategic Management
Management is often divided into three levels based on the type of management activity performed. z Strategic Management z Tactical Management z Operational Management
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z
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Management Levels z
z
An MIS in today's context is usually a mixture, with the computer being used for storage and processing of data, while the human processes come into play when judgment is called for, or when an unusual situation arises. Information technology is not essential to an MIS but it can be very useful. At higher levels of management, there is a greater amount of unstructured problems and decisions where human involvement is essential.
z Strategic
management deals with long range considerations. z Decisions to be made deal with the choice of business direction, market strategy, product mix, etc.
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Tactical Management
Operational Management
z Tactical
management has a medium term planning horizon. z It includes acquisition and organization of resources, structuring of work, and recruiting and training of personnel. ITM Lecture 7 Advanced Diploma (Thames College)
z Operational
management is related to short term decisions for current operations. z Pricing, production levels, inventory levels, etc, are the result of operational planning and control.
MIS for Operational Management z At
the operational management level, the main concern is with the implementation and control of the day-to-day activities of the organization. z Operational management require their MIS to provide them detailed control information about transactions. ITM Lecture 7 Advanced Diploma (Thames College)
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31
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MIS for Tactical Management Tactical level management implement strategic objectives and monitor operations. z Unlike MIS at the operational level, there is no best design for tactical level MIS. z In many cases, the MIS for tactical management is part of a transaction processing system. z Control systems with information feedback are essential to carry out the monitoring role and it is this level which administers most of the well known conventional control systems such as budgetary control, production control, inventory control and so on. z
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MIS for Strategic Management
Problems with MIS
Strategic planning and decision making involves setting a long term direction for the company. z Strategic management needs to understand the environment and predict key trends and challenges facing the organization in the future. z There is a need for MIS to obtain information about the environment by a scanning and information gathering process in order to identify potential threats and opportunities. z
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z
MIS cannot provide management with the information they need due to the following reasons: z z z z z z
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Competitive Forces
Strategic Role of Information Systems z Information
systems are no longer restricted to backroom support roles. z Organizations are increasingly aware of the potential strategic applications of information systems.
Michael Porter discussed 5 organization-level competitive forces in an industry which together determine how strong an organization is in its industry. z These forces are: z
z z z z z
ITM Lecture 7 Advanced Diploma (Thames College)
Lack of Management Direction Lack of management knowledge of computers Lack of top management support Lack of management participation in MIS design Management do not always know what information they need IT personnel often do not know enough about management to produce relevant information for the managers they serve
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Bargaining Power of Suppliers Bargaining Power of Buyers Threats of New Entrants Threats of Substitution Intensity of Rivalry ITM Lecture 7 Advanced Diploma (Thames College)
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Bargaining Power of Suppliers
Bargaining Power of Buyers
The bargaining power of suppliers is high if there are concentrated sources of supply and few substitutes. z If these near monopoly situations, the suppliers can push prices upward and can be indifferent about service or quality. z Information Technology can be used to reduce supplier power by developing in-house capability to produce or service or buying into a supplier. z
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z
z
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Threats of Substitution
When an industry experiences good profit margins, it is attractive for new entrants to join the industry and this will create downward pressure on prices due to the increased availability of products and service. An existing player in the market can create can entry barrier by using IT to make the cost too high for any new player. A new entrant can use IT to improve its services or product and thereby, overcome barriers set up by existing players. ITM Lecture 7 Advanced Diploma (Thames College)
buyer is high (e.g. when the buyer is large and/or the products are undifferentiated), then there is downward pressure on prices and upward pressure on both product quality and service. z Information Technology can be used to reduce buyer power such as increasing switching costs.
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Threats of New Entrants z
z When
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z Substitution
of products and services can reduce or eliminate the market for existing organizations and thereby weaken it. z A late entrant to the market may choose to introduce a product that is a technological advancement over the existing products in the market, and thereby weaken existing players by the threat of substitution. ITM Lecture 7 Advanced Diploma (Thames College)
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Intensity of Rivalry
Competitive Strategy
z The
intensity of rivalry in the market affects the overall profitability, and it is usually greater in mature or declining markets. z Price wars usually benefit the consumer and eliminate some of the weaker players in the market. z IT can be used to overcome the dilemma of having to lower prices while increasing levels of service. ITM Lecture 7 Advanced Diploma (Thames College)
z
Firms have discovered many different approaches and the best strategy for a given firm is ultimately a unique combination reflecting its particular circumstances. At the broadest level we can identify three internally consistent generic strategies for creating such a defendable position in the long and outperforming competitors in an industry: z z z
Overall Cost Leadership Differentiation Focus ITM Lecture 7 Advanced Diploma (Thames College)
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Competitive Strategy – Overall Cost Leadership
42
Competitive Strategy Differentiation
Cost leadership exists when a company can provide an "identical" product or service at the lowest cost in that industry. z Cost leadership requires aggressive construction of efficient - scale facilities, vigorous pursuit of cost reductions from experience, tight cost and overhead control, avoidance of marginal customer accounts, and cost minimization in areas like R&D service, sales force, advertising, and so on. z A great deal of managerial attention to cost control is necessary to achieve these aims. z
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z
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z An
organization may choose to provide a differentiated Unique product or service at a premium price in that industry. z The aim in differentiating the product or service offering of the term is to create something that is perceived industry-wide as being unique. ITM Lecture 7 Advanced Diploma (Thames College)
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Competitive Strategy - Focus z
z
z z
Information Technology Management
Focus its product or service provision on a particular buyer group, segment of the product line, or geographic market for an identified market segment, by either cost leadership or differentiation. The entire focus strategy is built around serving a particular target very well, and each functional policy is developed with this in mind. Able to serve its narrow strategic target more effectively or efficiently than competitors who are competing more broadly. Achieves either differentiation from better meeting the needs of the particular target, or lower costs in serving this target, or both. ITM Lecture 7 Advanced Diploma (Thames College)
Unit 17: Prototyping and Feasibility Study
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Problems with Classical SDLC
Prototyping and Feasibility Study
z User
Requirements Change z Incomplete User Requirements z Development Targets are Missed
Prototyping
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Problems with Classical SDLC User Requirements Change z z z z
Problems with Classical SDLC Incomplete User Requirements
Systems often take years to analyze, design, and implement. During development period, the environment and user needs is are constantly changing. The finished system might not meet the new applications environment. With the traditional SLDC approach, it is relatively difficult to respond to new needs once users have signed off on the requirements analysis and the design. ITM Lecture 7 Advanced Diploma (Thames College)
z z z z
z z
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Prototyping
Systems developers are often notoriously optimistic. Deadlines are set and missed; then re-set and often missed again. The systems usually require more resources than originally estimated and costs frequently climb over budget. Problems of miscommunication, omissions, and human error complicate matters. Projects are often cancelled as cost begin to exceed benefits and the probability of ever finishing them within a reasonable span of time becomes more and more remote. ITM Lecture 7 Advanced Diploma (Thames College)
z
People often cannot articulate what type of information they really need in their work. With the traditional SDLC approach, users do not really see the new system until it is installed. Many users have a difficult time visualizing the system by looking at a set of diagrams or specifications. Requirements analysis had to be repeated because additional requirements were discovered or because users changed their minds.
49
Problems with Classical SDLC Development Targets are Missed z
z
51
z The
process of building an experimental system quickly and inexpensively for demonstration and evaluation so that users can better determine information requirements. z By interacting with the prototype, users can get a better idea of their information requirements ITM Lecture 7 Advanced Diploma (Thames College)
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Phase 1: Define System Specifications
The Prototyping Process z Phase z
2: 3:
Refine the Prototype System.
z Phase z
of the rough spots in the prespecification approach to systems development has been the definition of system specifications.
Creating the Prototype System.
z Phase z
z One
Define System Specifications.
z Phase z
1:
4:
Develop Operational System. ITM Lecture 7 Advanced Diploma (Thames College)
Phase 2: Creating the Prototype System
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Phase 3: Refine the Prototype System
z Project
team members rough out the logic of the system and how the elements fit together and then work with the user to define the I/O interfaces.
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z Users
sit down at a terminal or PC and evaluate portions and eventually all of the prototype system. z The system is then expanded and refined to meet the users' total information needs.
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Phase 4: Develop Operational System z The
System Prototyping z Prototyping
involves a repetitive sequence of analysis, design, modeling and testing. z The end product of System Prototyping is a full-featured, working model of the information system, ready for implementation.
prototype system is custom coded.
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Design Prototyping
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Advantages of Prototyping
Design Prototyping is used to verify user requirements. z The end product of Design Prototyping is a userapproved design prototype that documents and benchmarks the features of the finished system. z
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z Most
useful when there is uncertainty about requirements or design solutions. z Valuable for the design of End-user interface of an Information System. z Prototyping encourages intense end-user involvement throughout the systems development lifecycle. z It is more likely to produce systems that fulfill user requirements. ITM Lecture 7 Advanced Diploma (Thames College)
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Disadvantages of Prototyping
Prototyping and Feasibility Study
z The
rapid pace of development can create quality problems, which are not discovered until the finished system is operational. z Other system requirements, such as reliability and maintainability, cannot adequately be tested using a prototype. z In very complex systems, the prototype becomes unwieldy and difficult to manage ITM Lecture 7 Advanced Diploma (Thames College)
z z
z
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Types of Feasibility
The Feasibility Study is one of the steps within the Preliminary Investigation Phase of the Systems Development Life Cycle (SLDC). The analyst learns from the user what is expected of the proposed information system. The analyst uses technical skills and knowledge to decide on various alternatives to be considered for implementation. The feasibility study has to contain enough detail so that an alternative can be selected for development. ITM Lecture 7 Advanced Diploma (Thames College)
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What is a Feasibility Study? z
Feasibility Study
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Different types of feasibility that must be evaluated in order to determine if the project is worth doing. z A feasibility study uses three major yardsticks to measure, or predict a system's success: z
z z z
Economic Feasibility Technical Feasibility Operational Feasibility
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Operational Feasibility
Technical Feasibility
zA
system that has operational feasibility is one that will be used effectively after it has been developed.
A systems request has technical feasibility if the organization has the resources to develop or purchase, install, and operate the system. z Project risk can be assessed based upon: z
z z z
z
ITM Lecture 7 Advanced Diploma (Thames College)
Project size Project structure Development group's experience with the application User group's experience with development projects and the application area ITM Lecture 7 Advanced Diploma (Thames College)
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Economic Feasibility
What is Costs?
A systems request has economic feasibility if the projected benefits of the proposed system outweigh the estimated costs involved in acquiring, installing, and operating it. z Before management will approve any large computer system, an appraisal of the benefits and costs of the system must be done. z Essentially what happens is that all costs associated with the proposed systems project is calculated, as well as the benefits to be derived from this system. z Then we use certain financial methods to rank projects. z
z
Among the cost items that are taken into consideration are hardware, software, personnel, and establishment of new procedures and representations of data. z Cost is divided into several types: z
Tangible Costs (can easily be measured in dollars) z
z
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Example: Hardware
Intangible Costs (cannot be easily measured in dollars) z
Examples: loss of customer goodwill, loss of employee morale
z
One-Time Costs (project startup, initiation and development)
z
Recurring Costs (ongoing use of the system)
z
z ITM Lecture 7 Advanced Diploma (Thames College)
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Example: System Development, Data Conversion Example: Software Maintenance ITM Lecture 7 Advanced Diploma (Thames College)
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What is Benefits? z
What is Requirement?
The benefits are divided into Tangible Benefits and Intangible Benefits. z
Requirement is a feature that users identify as being necessary or useful in a system. z How are requirements determined?
Tangible Benefits are those that can be measured easily (most readily translated into dollars). z
z
zA
The business must first be understood. z The problems are studied and opportunities for improvement are identified. z It is these opportunities that are eventually turned into statements of requirements.
Examples: Cost reduction, Opening new markets and increasing sales opportunities
z
Intangible Benefits are those that cannot be measured easily (difficult to quantify) z
Examples: Increased employee morale, Promotion of organizational learning and understanding ITM Lecture 7 Advanced Diploma (Thames College)
Importance of Requirements z z z z z
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Methods of Data Collection
The requirements stage is one of the early stages in SDLC. By studying both the existing and proposed systems in detail, various problems can be anticipated. It is important to consider how these problems can be solved or at least, how to minimize their impact. It is important that requirements are clear and complete. Subtle misunderstandings may result in defects which could be hard to detect. ITM Lecture 7 Advanced Diploma (Thames College)
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z Primary
data collection involves direct interaction with the source of the data. z Interview z Observation z Questionnaire z Documents
Review
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Interview z z z z
z
Observation
The systems analyst spends a great deal of time interacting with others, particular in interviews settings. Interviews have varying degrees of structure; for a first meeting there may be no structure at all. As the project progresses, more structured interviews are conducted. The analyst may wish to prepare in advance an interview schedule containing the questions to be asked and the pints to be covered. This will ensure that no pint is omitted or that the interview drifts from its original objectives. ITM Lecture 7 Advanced Diploma (Thames College)
technique for collecting data on a process is to observe that process. z Frequently in systems analysis and design we will Walkthrough system observing crucial information flows and decision points.
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Questionnaire
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Documents Review
zA
questionnaire allows us to collect data from a relatively large number of people at a reasonable cost. z A questionnaire can be thought of as a structured interview form with questions designed so that they can be answered without face-to-face encounter. z Designing a good questionnaire is a difficult task. ITM Lecture 7 Advanced Diploma (Thames College)
z One
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z Some
types of information may be obtained from reviewing existing company records or documents. z The existing work procedures or company policy may be reviewed to obtain information about the current business processes. z An examination may be made of company records concerning the volume of invoices or shipment to determine problem areas. ITM Lecture 7 Advanced Diploma (Thames College)
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Data Flow Diagrams (DFD)
Problems of Conventional Flowcharts
zA
Data Flow Diagram (DFD) is a graphical tool to depict the flow of data through a system and the work or processing performed by that system.
z Lack
of discipline or structure. z Very few guidelines on how to develop flowcharts z Flowcharts for complex systems are often unreadable. ITM Lecture 7 Advanced Diploma (Thames College)
It shows how data moves through an information system but does not show program logic or processing steps. z It only represent a logical model that shows what the system does, not how it does it. z
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Data Flow Diagrams z
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DFD Symbols/Elements
Data Flow Diagrams (DFD) require only four symbols, making them very easy to create. z
z z z
z
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Open-ended rectangles represent store of data, such as a file of items in inventory, their quantity, and the Economic Recorder Quantity ( EOQ). Circles stand for some type of processing, and arrows represent the flow of data. A square is a source or destination of data. Dataflow diagrams should also be prepared in a topdown manner.
The context diagram is a summary diagram of the first level DFD and serves to put the system under study in its context within the business environment. ITM Lecture 7 Advanced Diploma (Thames College)
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Data Flow Diagrams (DFD)
Decomposition of Context Diagram
z Tool
that graphically shows flow of data in system
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Context Diagrams
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Level 1 Diagrams
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Entity Diagrams
Entity-Relationship Diagram (ERD)
z
z Tool
that graphically shows connections between entities in system
z z z
z z
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Systems Implementation and Development Tools
Information Technology Management
Unit 18: Systems Implementation and Development Tools
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An entity is an item of interest to the organization like a department, staff, machines, customers, etc. An entity diagram shows the relationships between such items of interest. Take the example of a department and its staff, both of which are entities. The relationship between these entities can be shown by drawing a diagram linking them together. We could also show a particular kind of relationship like one to many. The entity diagram can be used to understand and communicate the relationships between entities. The data fields (attributes) associated with each entity may also be documented.
Conversion
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Conversion Tasks z
z
z
z
Data Conversion Methods
To ensure a smooth and successful implementation, users must be familiar with the features of the system, operators must know how to make the system function properly, and the conversion itself must go off smoothly. Conversion includes the creation of all required files and database, establishing a backup copies, and converting tested programs to operating status. Data conversion is a central part of a system conversion regardless whether the preceding system was manual or computer-based. The data conversion must be carefully planned and also crosschecked to see that it is done right. ITM Lecture 7 Advanced Diploma (Thames College)
are fours strategies, the choice of which is dictated by the given situation z Parallel
Systems z Direct Cutover z Pilot System z Phase-in of System
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Data Conversion Methods – Parallel Systems
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Data Conversion Methods – Direct Cutover
A safe and conservative conversion approach z Running both old and new systems for a period of time z The output of the new system is compared closely with the output of the old system and any difference reconciled z When users are comfortable that the new system is working properly, the old system is eliminated z Very expensive, additional staff is required. z
ITM Lecture 7 Advanced Diploma (Thames College)
z There
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z
z z z
This method of conversion require much more careful and detailed planning than the other alternatives. A risky conversion approach in which the new system completely replaces the old one on an appointed day. Involves stopping the old system and starting the new system on a specific date. High potential for problems and errors. Less costly if no problem, otherwise more costly. ITM Lecture 7 Advanced Diploma (Thames College)
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Data Conversion Methods – Pilot System
Data Conversion Methods Phase-in of System
z Involves
running the new system for one group of uses rather than all users z When the pilot system runs without problems then it is rolled out to the other users
z z
z
z
ITM Lecture 7 Advanced Diploma (Thames College)
Piecemeal approach Components of the new system are slowly phased in while components of the old system are slowly phased out Allows the organization to being taking advantage of the newly developed support tools while retaining flexibility to cope with any deficiencies When everyone is confident that the new system is performing as expected, then the old system is completely phased out ITM Lecture 7 Advanced Diploma (Thames College)
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Systems Implementation and Development Tools
94
Classroom Training z Classroom
training involves a live instructor conducting training for students.
Training
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Advantages z
Disadvantages
Classroom training has several strong advantages over other forms of training, which do not use live instructors. z z
z
z
z
z
Feedback is immediate when the problems occur. Both the Learners and the teachers can ask questions to gauge the group's understanding. The teaching can be tailored to the learners by adding company-specific examples or job-specific examples. The classroom is a familiar and acceptable environment for most people.
ITM Lecture 7 Advanced Diploma (Thames College)
z
z
z
It is usually more expensive than mediated training without instructors. Training facilities are expensive, particular, if hands-on computer training is to be done. Users have to wait until a class starts to get the training they need. Teaching quality can vary considerably from course to course.
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Internal vs. External Training
98
Advantages of Internal Training
z If
the company decides to sponsor training, the next step is to decide whether to do it internally or whether to contract the training out to external vendors.
ITM Lecture 7 Advanced Diploma (Thames College)
On the negative side, classroom instruction also has a number of strong disadvantages.
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z Many
firms use internal training because it has several important advantages. There is greater control over quality. If there are quality problems, these can be overcome. With external training, there is less control over quality. z Courses can be tailored to the corporation by including company-specific information. z
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Advantages of External Training z
Summary
External vendors offer a number of advantages over internal training. z
z z
If internal training is done in geographically decentralized organizations, the use of external vendors can provide cheaper local training when popular application software packages or the basic use of the computer are to be taught. Unless a firm has a very large training program, external training will be less expensive. For popular software packages or basic machine use, external vendors will offer courses almost continuously, whereas internal programs may offer these course less frequently. ITM Lecture 7 Advanced Diploma (Thames College)
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Systems Implementation and Development Tools
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Development Tools Computer Aided Software Engineering (CASE) is the use of computer technology to help improve application systems development. z The earliest CASE tools were used to create flowcharts and data flow diagrams. z Later versions of CASE allowed computer professionals to create complete and detailed specifications and to later generate structured program code. z The CASE software can then generate a detailed documentation package for easy maintenance. z
Development Tools
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Features of CASE – Draw Descriptive Diagrams
Features of CASE z CASE
consists of a set of workstationbased software tools designed to support application developers. z The activities that most CASE tools include are described below. z Draw
Descriptive Diagrams z Maintain Data Dictionary z Design Display Screens z Design Output Layouts ITM Lecture 7 Advanced Diploma (Thames College)
tools provide the developer with the ability to draw various types of diagrams like data flow diagram, flowcharts, etc.
z Making
modifications to diagrams is much faster with this tool. ITM Lecture 7 Advanced Diploma (Thames College)
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Features of CASE – Maintain Data Dictionary
106
Features of CASE – Design Display Screens
z This
is used to store and validate definitions of data items used in the system.
z It
also records the programs or tables where each data item is used.
ITM Lecture 7 Advanced Diploma (Thames College)
z Diagramming
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z CASE
is used to quickly create screen designs and to generate the code based on this design. z These can be reused in other applications. z Screen intensity, use of reverse letters and inclusion of underlining are all easily specified. ITM Lecture 7 Advanced Diploma (Thames College)
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Features of CASE – Design Output Layouts
Benefits of CASE z What
z As
with screen designs, CASE tools can also be used to design report layouts.
z Development
time is shortened z Development standards can be enforced. z Data Dictionary is automatically produced
z Consistency
between reports can be achieved by starting with one standard template.
ITM Lecture 7 Advanced Diploma (Thames College)
are the benefits of using CASE?
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Benefits of CASE – Development Time is Shortened
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Benefits of CASE – Development Standards can be Enforced
z With
automated tools, the effort required to complete each task is lessened.
z Standards
z For
example, instead of drawing data flow diagrams by hand, it can be done with CASE.
define the rules for certain development decisions. z Having these standards embedded in software ensures it is more consistently performed. z For
example, an organization may have standards regarding the naming convention of data fields or the diagramming method.
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Benefits of CASE – Data Dictionary is Automatically Produced
Limitations of CASE
z There
is no need to review the entire system to ensure that the data dictionary is complete and consistent if each data field is defined in the data dictionary at its point of creation.
ITM Lecture 7 Advanced Diploma (Thames College)
software is not able to support the full development life cycle. z The design to code transformation is not fully automated, and results in much analyst and the programmer effort anyway.
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User Documentation
are two types of documentation
z
z User
Documentation z Operations Documentation
z
z z
ITM Lecture 7 Advanced Diploma (Thames College)
not support the full SDLC
z CASE
113
Documentation z There
z Does
115
The first type of documentation is the User Manual, also known as the User Guide. The user manual contains screen and report layouts, with explanation of how to use a transaction, or read a report. It also has other features like a list of error conditions and how to correct error. The user manual should be referred to by the user who has a question or a problem about the system before he or she refers to the IT person supporting the application. ITM Lecture 7 Advanced Diploma (Thames College)
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Operations Documentation z z z
z
z
Importance of Documentation
The operations section of an IT department has to operate the system after it has been implemented. This group needs information on normal operating procedures and on how to respond to errors. The Operations Manual will contain information about starting and shutting down the system, plus details about how to run the batch jobs. For each batch job, a complete systems flowchart that shows the input required, the files necessary, and any printed output must be documented. It is important for operators to know possible error conditions and how to respond to them. ITM Lecture 7 Advanced Diploma (Thames College)
particularly so if there is a deadline approaching and if the tasks are behind schedule. z Documentation must be treated as part of the complete package of deliverables. z Why is documentation important ? z Manage
the Project z Obtain Consensus ITM Lecture 7 Advanced Diploma (Thames College)
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Manage the Project
118
Obtain Consensus
z Documentation
is a tool used to manage the development process. This is done in a few ways. z It
is used to review tasks which have been completed or which are going to be done. z It is used to monitor progress and take corrective action. z It is used to make decisions on future tasks. z It is the tools used to manage the development process, to control its activities and plan future steps. ITM Lecture 7 Advanced Diploma (Thames College)
z This
119
z In
any complex task involving many parties, there is always a possibility of misunderstanding. z The agreement should be documented and a copy sent to all parties involved for feedback and agreement. While this does not guarantee that there will not be any miscommunication, it does minimize it. ITM Lecture 7 Advanced Diploma (Thames College)
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Questions & Discussion
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