Determining Requirements

Systems Analysis: Determining Requirements

CSC 2202 Systems Analysis and Design

1

Objectives 1. Learn how the current system works 2. Determine and document fully how the system could work better 3. Explain when and how to use fact-finding techniques

CSC 2202 Systems Analysis and Design

2

Overview Requirements determination addresses the gathering and documenting of the true and real requirements for the Information System being developed. Requirements is the wants and /or needs of the user within a problem domain.

CSC 2202 Systems Analysis and Design

3

Overview (cont) Fact-finding techniques  Interviewing  Documentation review  Observation  Questionnaires  Sampling  Research Methods used to record results CSC 2202 Systems Analysis and Design

4

Overview (cont) Systems analysis phase tasks  Gather and record facts about the current system and what is required to support business needs Three-step approach to decision-making  Determine the facts  Analyze the facts  Make a decision

CSC 2202 Systems Analysis and Design

5

Overview (cont) Systems Analysis phase has 3 steps

CSC 2202 Systems Analysis and Design

6

Overview (cont) Two steps in the systems analysis phase  Requirements determination (fact-finding)  Requirements analysis

CSC 2202 Systems Analysis and Design

7

The Challenge of Systems Analysis Requirements determination questions  Who

does it?  What is done?  Where is it done?  When is it done  How is it done  Why is it done?

CSC 2202 Systems Analysis and Design

8

The Challenge of Systems Analysis Requirements analysis questions  Who

should do it?  What should be done?  Where should it be done?  When should it be done?  How should it be done?

CSC 2202 Systems Analysis and Design

9

The Challenge of Systems Analysis Requirements determination questions  Who does it?  What is done? 

Where is it done?



When is it done



How is it done

Requirements analysis questions  Who should do it?  What should be done?  Where should it be done?  When should it be done?  How should it be done?

CSC 2202 Systems Analysis and Design

10

Systems Requirements Characteristics or features that must be included to satisfy business requirements  Outputs  Inputs  Processes  Timing  Controls  Volumes. sizes, and frequencies CSC 2202 Systems Analysis and Design

11

Gathering Information Need to have a checklist of types of information / documentation to gather. Challenges are : Where to look for information When to stop looking for information i.e. how much is enough

CSC 2202 Systems Analysis and Design

12

Categories of Information Categories of information are: Information about the Organisation Information about the People Information about the Work Information about the Work Environment

CSC 2202 Systems Analysis and Design

13

Categories of information checklist *

CSC 2202 Systems Analysis and Design

14

Information about the Work Tasks and work Flows  Here

Paper Flow Diagrams are a helpful technique

Methods and procedures for performing the work  Here

System Flowcharts - show both manual and automated tasks CSC 2202 Systems Analysis and Design

15

Work flow diagram Process models help people without business (domain) expertise understand how things work. A work flow diagram makes problem areas visible Shows the impact of proposed changes. It reduces the probability of omitting critical aspects of your solution.

CSC 2202 Systems Analysis and Design

16

Paper flow diagram *

CSC 2202 Systems Analysis and Design

17

System flowchart symbols

*

CSC 2202 Systems Analysis and Design

18

PCC Fig 8.4 System Flowchart

CSC 2202 Systems Analysis and Design

19

Information about the Work Environment Physical arrangements of the work areas Resources available  Desks  Files  Personal

computers  Computer terminals CSC 2202 Systems Analysis and Design

20

Sources of Information Existing documentation includes:  Organization

charts  Methods and procedures manuals  Job descriptions  Forms and reports  Paper / document flow diagrams  System flowcharts CSC 2202 Systems Analysis and Design

21

Sources of Information (cont)  Policy

manuals  Computer program documentation  Data dictionary listing  Computer operation manuals  External sources (other companies, vendors)

CSC 2202 Systems Analysis and Design

22

Methods for Gathering Information  Interviews  Questionnaires  Observation  Documentation

review

 Sampling  Research  Measurement

CSC 2202 Systems Analysis and Design

23

Interviews Interviews Is a planned meeting during which you obtain information from users of the existing system. Conversation with a specific purpose.

CSC 2202 Systems Analysis and Design

24

Planning for the interview Try to answer the following questions  What

do you wish to achieve from the interview?  Who should be interviewed?  How will these interviews be conducted?  What topics are to be covered in the interview?  Where will the interview take place? CSC 2202 Systems Analysis and Design

25

Planning for the interview (cont) Obtain approval from senior management Plan who needs to be interviewed (refer to the organisation chart) First interview managers, then operational personnel  helps gain support for the new project

CSC 2202 Systems Analysis and Design

26

Planning for the interview (cont) Prepare for the interview write down objective for interview write some questions - prepare to probe further Make appointment, on “home” ground Send outline of questions / information sought CSC 2202 Systems Analysis and Design

27

Planning for the interview (cont) Prepare for the interview Make an appointment  Place a reminder call  Send a memo to managers  Create a list of questions  Use a variety of questions 

Open-ended questions  Closed-ended questions  Range of responses questions 



Send confirmation memo to interviewee

CSC 2202 Systems Analysis and Design

28

Structure of a fact finding interview It should have A

social chart – put interviewee at ease  Overview – an outline of areas to cover  Questions and answers 

well structured with a four step questioning model having; questions, problem, implications and requirement.

 Closing

CSC 2202 Systems Analysis and Design

29

Conducting the interview Preferably interview one-to-one Listening tactics - encourage interviewee to talk Interviewer comments should be noncommittal e.g. office politics Minimal note taking Use a cassette? CSC 2202 Systems Analysis and Design

30

Conducting the interview Avoid leading questions Open-ended vs. closed questions Write up interview notes immediately after the interview As courtesy, send written thanks for interview accompanied by your interview summary CSC 2202 Systems Analysis and Design

31

Interviews Open ended interview questions

CSC 2202 Systems Analysis and Design

32

Interviews Closed interview questions

CSC 2202 Systems Analysis and Design

33

Interviews Evaluate the interview Identify possible biases  Determine whether interviewees have necessary experience  Be able to separate his/her opinion from facts and fictions from facts. 

Unsuccessful interviews Not all interviews are successful  Find a way to conclude an unsuccessful meeting  Consider alternatives 

CSC 2202 Systems Analysis and Design

34

Interview advantages and disadvantages Advantages Personal contact - face-to-face Flexible and adaptive SA can probe for further detail Best source of qualitative information I.e. opinions of people, policies, and subjective description of activities and problems. Useful for respondents who do not communicate properly in writing or are lazy to complete questionnaires. CSC 2202 Systems Analysis and Design

35

Interview disadvantages Disadvantages Time consuming Evaluation of information can be difficult Biased by interviewer Subjective and sometimes irrelevant. Communication problems Misunderstandings can rise from different user values, or technical jargons by the SA. CSC 2202 Systems Analysis and Design

36

Interviews - summary Determine the people to interview Establish objectives for the interview Prepare for the interview Conduct the interview Document the interview Evaluate the interview Unsuccessful interviews CSC 2202 Systems Analysis and Design

37

Questionnaires Requests specific information from respondents impersonal often mass produced method for gathering information from many people

CSC 2202 Systems Analysis and Design

38

Questionnaires design There are three sections to consider when designing a questionnaire A heading section A classification section A data section

CSC 2202 Systems Analysis and Design

39

Questionnaires design Heading section Describes the purpose of the questionnaire and contains the main references- name, staff identification number, date.

CSC 2202 Systems Analysis and Design

40

Questionnaires design A classification section  For

collecting information that can later be used for analysis and summarizing the total data, such as age, sex, grade, job title, location

A data section  Has

questions designed to elicit the specific information being sought.

CSC 2202 Systems Analysis and Design

41

Questionnaires design Guidelines …..  Should

begin with a preamble  Bear in mind the level of intellect and the level of interests of the respondents  Keep questions short, unambiguous and unbiased, and where possible have multianswers.

CSC 2202 Systems Analysis and Design

42

Questionnaires design  If

possible avoid too much branching.  If the survey is extensive, you may consider use of automated means of reading responses.  Pretest the questionnaire before using it for the purpose of checking whether all the questions will be easily understood.

CSC 2202 Systems Analysis and Design

43

Good questionnaires characteristics Validity 

questionnaire does what it is intended to do

Reliability constant responses should be achieved  same info sought through separate questions 

Ease of administration and analysis directions stated clearly  questions in logical order  questions should be easy to answer  if possible, structure for machine analysis 

CSC 2202 Systems Analysis and Design

44

Questionnaire distribution Plan on how questionnaire will be administered  mail  Phone  Fax  Post  personal

delivery CSC 2202 Systems Analysis and Design

45

Writing questionnaire items open-ended fill-in-the-blank multiple choice rating scales ranking scales

CSC 2202 Systems Analysis and Design

46

Open-ended vs. closed questions Closed questions on questionnaires can help ensure responses

CSC 2202 Systems Analysis and Design

47

Questionnaire – Advantages & disadvantages Advantages Most economical from large number of people Administer quickly and easily Results can be analysed quickly Can get reliable information due to anonymity. Allow collection of data and can be filled in at leisure. CSC 2202 Systems Analysis and Design

48

Questionnaire – Advantages & disadvantages Disadvantages effective q’aires are difficult to construct need several drafts and trial mailing gathers only limited amount of data no flexibility to adapt to each respondent to probe more deeply Misinterpretation of the question. CSC 2202 Systems Analysis and Design

49

Questionnaires - summary Questionnaires Brief and user-friendly  Clear instructions  Questions in logical order  Simple wording to avoid misunderstanding  Avoid leading questions  Open-ending questions are difficult to tabulate  Limit questions raising concern/negative issues  Section for general comments  Test the questionnaire in advance 

CSC 2202 Systems Analysis and Design

50

Observation 

Systems Analyst participates in or watches a person perform activities to learn about the system.



often used when validity of data collected through other methods is in question or when the complexity of certain aspects of the system prevents a clear explanation by the end users.



People usually feel uncomfortable when being watched. CSC 2202 Systems Analysis and Design

51

Observation Observation  Ask

questions about present system operation  Observe all steps in the processing cycle  Examine each form, record, and report  Consider each person working with the system  Talk to people who receive current reports CSC 2202 Systems Analysis and Design

52

Observation Observe actual processing associated with the system Data gathered based on what is seen (not on what people say happens in the system) Work flow in an office follow paperwork from the time a source document is created to when it is filed permanently  document using paper flow diagrams 

CSC 2202 Systems Analysis and Design

53

Observation- Advantages and disadvantages Advantages of Observations  Permits correction of any misconceptions or erroneous impressions made before.  Permits verification of statements made in interviews as well as determine if procedures operate as specified in the system documentation.  You become better acquainted with the operating personnel who will be implementing the new or changed system.  information gathered is “highly believable” CSC 2202 Systems Analysis and Design

54

Observation - Advantages and disadvantages Disadvantages logistic problems performance of people being observed may be affected by the observer’s presence trained people needed for observations Sample observation form CSC 2202 Systems Analysis and Design

55

Measuring It is important in systems investigation, analysis and design in terms of: Magnitude of the exercises  Processes  Quantity of work  Time taken to accomplish work (time frame works)  Rates of doing work  Intervals 

These help to determine the systems requirements, e.g software, hardware. CSC 2202 Systems Analysis and Design

56

Prototyping Experimenting with the system under development 

A method used to test or illustrate an idea and build a system in an explorative way.



Used to discover user requirements



Allows analyst to quickly create mock forms and tables to simulate the implemented system.

CSC 2202 Systems Analysis and Design

57

Prototyping .

Identify basic User requirements Rapidly develop prototype Enable users to work with the prototype

Throwaway Perform further System devt With life Cycle, discard prototype

Obtain user feedback Modify the prototype

“Evolutionary Development” – complete&document the final version, field it as the operational system

CSC 2202 Systems Analysis and Design

58

Prototyping Advantages of a Prototype  Valuable for the design of the end user interface of an IS. Users’ needs and behavior are not entirely predictable and are strongly dependent on the context of the situation. So it enables users to react immediately to the parts of the system they will be dealing with.  It is more likely to produce a system that will fulfill user requirements, especially when it is used for decision-support applications.

CSC 2202 Systems Analysis and Design

59

Prototyping  It

promises to eliminate excess development costs and design flaws that occur when requirements are not fully captured the first time round.  User satisfaction and morale are usually heightened because users can be presented with an actual working system, preliminary though it may be in a very short period of time. CSC 2202 Systems Analysis and Design

60

Prototyping Disadvantages  Prototyped systems still need to be fully documented and tested, but often these steps are shortened.  The final step to convert the prototype into a polished production system may not be carried out. I.e. if it works reasonably, management does not / may not see the need for reprogramming and redesigning. CSC 2202 Systems Analysis and Design

61

Other Fact-Finding Techniques Document review Research

CSC 2202 Systems Analysis and Design

62

Requirements Determination Framework Requirements determination is the General data-gathering activity done during analysis. It has 4 sub activities:    

Requirements Anticipation Requirements Elicitation Requirements Assurance Requirements Specification

CSC 2202 Systems Analysis and Design

63

Requirements Determination Framework Requirements Anticipation – the SA hypothesizes that particular requirements are relevant based on his or her previous experience with similar systems and knowledge about the problem domain. Requirements Elicitation – the SA gathers the essential requirements from the user employing a variety of techniques, such as interviews and questionnaires. CSC 2202 Systems Analysis and Design

64

Requirements Determination Framework 3. Requirements Assurance – the SA validates

and verifies the requirements with the user as being the real and essential requirements. 4. Requirements Specification – the SA explicitly catalogues and documents the requirements either during or after the elicitation and assurance activities.

CSC 2202 Systems Analysis and Design

65

The “PIECES” Framework Focuses on the actual work of doing requirements determination. The model is used to classify identified requirements into one of six subject areas of Performance, Information, Economy, Control, Efficiency, and Services.

CSC 2202 Systems Analysis and Design

66

The “PIECES” framework P I E C E S

- Performance - Information - Economy - Control - Efficiency - Services CSC 2202 Systems Analysis and Design

67

The “PIECES” framework Performance 

Is current throughput and response time adequate?

Information 

Do end users and managers get timely, pertinent, accurate and usefully formatted information?

CSC 2202 Systems Analysis and Design

68

The “PIECES” framework Economy  Are services provided by the current system cost-effective?  Could there be a reduction in costs and/or an increase in benefits? Control  Are there effective controls to protect against fraud and to guarantee information accuracy and security?

CSC 2202 Systems Analysis and Design

69

The “PIECES” framework Efficiency  Does current system make good use of resources: people, time, flow of forms? Services  Are current services reliable?  Are they flexible and expandable? CSC 2202 Systems Analysis and Design

70

Review questions – Information Gathering 1. Describe four different categories of information that can be gathered and explain the relevance of each category to the systems development process. 2. Discuss the advantages and disadvantages of interviews as an information gathering process. 3. Discuss the importance of using a combination of information gathering techniques and tools to support systems development process. CSC 2202 Systems Analysis and Design

71