Mis Notes

System Analysis & Design

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System Group of components related to each other and work together to achieve a common goal are collectively called a system.

 Characteristics of System ♦

Group of components

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Related components

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Components work together

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Common objectives

Information System A system, which collects data from various, sources and processes that data to create meaning full information for its users.

For Example, Information office in our college is and information system. Information department of Sitara Textile is an example of information system.

Computer Based Information System (CBIS) It is information in which computer plays an important and integral pro. Computer is the basic components of computer based information system.

Components of computer based information System Hardware

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Software People Procedure Database  Hardware The physical components in the information system, which can be touched, are called hardware. For Example Hard disk, monitor, printer etc

 Software Set of instruction according to which the computers of information system worked are collectively called software.

 Peoples These are most important components in CBIS. People control the overall work of CBIS. There are different types of peoples work in CBIS.

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Programmers

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Data Entry Operators

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Network Administrator

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Database Administrator

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System Analyst

 Procedure There are the rules and regulations, which are followed in the CBIS. For Example Examples are Security procedure, backing procedure etc.

 Database It is a structure of related data about the organization in which information system is working. All the data is visually stored in the database. It was not used in older CBIS but database is not important part of computer based information system of mordner based.

Management of information

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system It is an information system, which collects data from internal and external resources of an organization and processes that data to fulfill the needs of all the levels of management.

There are four subsystems of MIS.

Transaction Processing System (TPS) Management Information System (MIS) Decision Support System (DSS) Office Support System (OSS)  Transaction Processing System (TPS) These systems are used to record day-to-day transaction of an organization. These are very low-level information system. Sales processing system is a transaction system.

 Management Information System (MIS) MRS is the natural extinction to the transaction processing system. These systems get data from TPS and create reports according the names of different levels of management.

 Decision Support System (DSS) DDS also get data from TPS and used it to help decision makers in making their decision. These systems are just to help decision maker and these system cannot make decision maker.

 Office Support System (OSS) These are information system, which provide support in office work like ward processor, spread sheet etc. These information systems also provide facilities of communication of information.

Level of management There are three types of level, of management.

Upper Level Manager (ULM) Middle Level Manager (MLM) Low Level Manager (LLM)

 Upper Level Manager (ULM)

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♦ Long-term planner usually plans for lifetime of organization. ♦ Few in numbers ♦ Take decision about the over all work of organization. ♦ There is more risk in their decision-making.

 Middle Level Manager (MLM) ♦ Short term planners (plan for month to year of an organization) ♦ Usually are departmental head ♦ Higher manager’s decisions effect their decision ♦ Less risk in their decision ♦ Take both structure and unstructured decision ♦ Usually in reasonable amount.

 Low-level managers ♦ Very short term planners (day to month) ♦ Supervision type job ♦ Large in numbers ♦ Higher-level manager’s decisions effect their decision ♦ Usually take structured decision ♦ Less risk involve in their decision

Expert System Expert system is software, which work like a human expert & can take decision according to the certain problems & can also provide helpful suggestions for decision making. Human experts usually feed their knowledge in expert system & then expert system take decision by using that knowledge. Expert system has not general knowledge. Expert system are usually develop for specific area of interest.

MYCIN is, world’s first Expert System.

For example, Xcon is an expert system used by DEC (Digital Electronic Corporation) to find the problem in their computing equipment or computer.

Types of Decision

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Structured Decision Unstructured Decision Semi Structured Decision  Structured Decision There are predefined decisions we have some formula or rules to take these decisions.

 Unstructured Decision These are no certain to make these decision but these decisions are only taken by experience and knowledge.

 Semi Structured Decision These decisions lie between structured and unstructured decisions. These decision which have the flavor of the both structured and unstructured. Structured and unstructured are collectively called semi structured decision.

System Development Life Cycle It is a step-by-step approach to develop and maintain a system. In development of information system SDLC is used very successfully now a days.

SDLC was first purposed by national computing center in 1964. There are 8 stages of SDLC.

Identifying Problem Feasibility Study Detail Investigation System Analysis System Design System Development

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Testing and Implementations Review and Maintenance SDLC is a step-by-step approach but not sequential approach.

 Identifying Problem It is the phase in which the problem is identified for which system will be created.

 Feasibility Study In this stage the problem is checked and analyzed that is their any solution of this problem. If there is a possible solution according to the situations feasibility of the project exist.

In this phase we study three types of feasibility. ♦ Technical Feasibility ♦ Operational Feasibility ♦ Economic Feasibility

 Detail Investigation In this phase problems are investigated in detail. In this phase it is checked that what are the problems and also user requirements are gathered. Usually detail investigation is done by four methods.

♦ Interviews ♦ Questionnaires ♦ Document Review ♦ Observation

 System Analysis In this phase different solutions for the problems are analyzed and best possible solutions chosen in this stage.

 System Designer In this stage design of a system is created according to the chosen solution. Data flow diagram, flow charts and entity relationship diagram are created in this phase.

 System Development In this phase system is developed according to the design. Programs are developed, hard ware and peoples are selected.

 Testing & Implementation

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In this phase system is tested and checked for performance. if it provides planned results system is implemented.

 Review & Maintenance After the implementation of system is review after specific time period for performance. If there is any problem in working of system is maintained to show desired result in this phase.

System Analyst Programmers developed many years back systems and the programmers do all the investigation and analysis. Programmers were good at programming and they know about operating and hard ware systems of computers but they are not good enough to understand business system. So they always get poor information system requirements. So in those days very few information systems were succeeded and many work disastrous. Then system analyst came into being. He is a person who is expert in programming and computer technique. But he also knows business systems very well. He is just like bridge between programmer and business environment. He is used in nearly all the stages of system development life cycle.

Techniques of System Investigation There are four method of investigation.

 Interviews It is face-to-face communication between interviewer and interviewee. It is a good way of getting to the point information but it is expensive and time-consuming method. This method is used when there is a lot of time to investigate and interviewees are small in numbers. Efficiency of interviews depends upon interviewers.

 Questionnaires It is less expensive method than interviews but may not provide to the point information. It is used to investigate to large no of peoples in short time. Efficiencies of questioners depend on how accurately they are design.

 Documents Reviews It is the method of examining document exists in a system. Usually this method is used before taking interviews from the interviewee.

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 Observation

It is the method in which system analyst or investigators get users information by observing their work. It is also used before the interviews and questionnaires.

Data Description Techniques There are three types of data description technique.

Data Flow Diagram (DFD) Entity Relationship Diagram (ERD) Flow Charts  Data Flow Diagram (DFD) DFD is used to represent all the data in a system; flow of data from one point to another and processes applied on the data. DFD is used to describe a system. System analysts communicate with each other with the help of DFD.

 Entity Relationship Diagram (ERD) ERD is usually used to create or describe a database and show entities in a system and relationship among entities in a graphical form.

 Flow Charts ♦

Flow charts are used to represent data flow and processes in sequenced form. Usually system analyst and programmers communicate with each other by using flow charts.

There are three types of flow charts.

♦ Program flow charts. ♦ System flow charts ♦ Run flow charts.

Reports Queries are very good in getting data from tables or existing queries but queries cannot show data to the users in user friendly way. Reports are used for this purpose. Reports can get data from tables or queries and provide that data to the user in an elegant way. There are three types of reports.

Detail Reports Summary Reports

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Exception Reports  Detail Reports These are regular reports and created after a specific period of time. In these reports information is provided in detail.

 Summary Reports It is also regular and time specific reports. It is based on detail report but it shows information in summaries form like totals.

 Exception Reports It is report that is but regular and time specific. It is created when something unusual happened. Some thing is very good or very bad. It can be created twice in a day or never in a year.

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