Modern Systems Analysis and Design Third Edition

1. Modern Systems Analysisand DesignThird Edition Chapter 7 Determining System Requirements 7.1

2. Performing Requirements Determination • System Analysis phase has three sub phases • Requirements determination • Requirements structuring • Generating alternative design and selecting best one • Gather information on what system should do from many sources • Users • Reports • Forms • Procedures

3. Performing Requirements Determination • Characteristics for gathering requirements • Impertinence • Question everything • Impartiality • Find the best organizational solution • Relaxation of constraints assuming anything is possible • Attention to detail • Reframing • View the organization in new ways 7.3

4. Deliverables and Outcomes • Types of deliverables: • Information collected from users interview transcripts, questionnaire responses, notes of observation • Existing written information sample business forms and reports, procedure manuals, training manuals • Computer-based information CASE repository contents and reports of existing system • Understanding of organizational components • Business objective • Information people needs • Data handled and when, how and who moves data • Rules of data processing • Key events 7.4

5. Traditional Methods for Determining Requirements • Individually interview people who knows current system • Survey people via questionnaires • Interview group of people with different needs • Observe workers at selected times to see how data is handled • Study business documents Interviewing and Listening Guidelines for Effective Interviewing • Prepare interviewee: set up appointment time and duration convenient for interviewee • Prepare checklist, agenda and questions: to know the sequence and duration of questions to ask • Listen carefully and take notes • Review notes within 2 days of interview • Be neutral and seek diverse views 7.5

6. Traditional Methods for Determining Requirements • Choosing Interview Questions • Open-Ended questions • No pre-specified answers like what you think about …? • Advantages: give interviewees more sense of involvement; put interviewee at ease as they respond in their own words • Disadvantages: takes long time to answer; difficult to summarize • Close-Ended questions • Respondent is asked to choose from a set of specified responses • Examples: True or False, Multiple choice, rating a response • Advantages: takes less time to answer and more topics covered • Disadvantages: useful information may be overlooked • Additional Guidelines • Do not phrase questions in ways that imply a wrong or right answer • Listen very carefully to what is being said – take notes or record • Type up notes within 48 hours • Do not set expectations about the new system 7.6

7. Traditional Methods for Determining Requirements • Administering Questionnaires • Questionnaires Vs Interviews • Interviews are very expensive and time-consuming • Questionnaires are not expensive and can gather information from many people simultaneously in a relatively short time • Interviews can have limited number of questions and limited number ofpeople contacted • Questionnaires give less depth of understanding as they provide no direct means to ask follow-up questions • Interviews provide the opportunity to judge the truthfulness of responses by the words or voice tone or the body language of the respondent • Questionnaires do not provide the opportunity to judge the accuracy of responses 7.7

8. Traditional Methods for Determining Requirements • Choosing Questionnaire respondents– if more people to survey decide which set of people to send questionnaire to or which questionnaire to send to which group of people • Convenient: people at a local site or willing to get surveyed • Random sample: select any person from a list • Purposeful sample: select people who satisfy certain criteria • Stratified sample: select random set from each of many categories • Designing Questionnaires • Questionnaires are most useful when used for specificpurpose and not for general information gathering • Questionnaires typically include closed-ended questions • Questionnaires must be extremely clear in meaning and logical in sequence as any doubts cannot be cleared How often(?) do you backup your computer files (C: or hard disk)? a) frequently b) sometimes c) hardly at all d) never 7.8

9. Traditional Methods for Determining Requirements • Interviewing Groups – interview several key peopleat once by several analysts, one asks questions other takes notes • Advantages • More effective use of time • Enables people to hear opinions of others and to agree or disagree • Disadvantages • Difficulty in scheduling convenient time as many people are involved • Nominal Group Technique • Facilitated process to support idea generation by groups • Individuals work alone to generate ideas which are pooled under guidance of a trained facilitator which are then discussed and then number of ideas are reduced and carry forward • Directly Observing Users • People cannot always be trusted to reliably report their own actions • Often difficult to obtain unbiased data • People often work differently when being observed 7.9

10. Analyzing Procedures and Other Documents • Types of information to be discovered in a document: • Problems with existing system • Opportunity to meet new need • Organizational direction • Titles and names of key individuals • Values of organization • Special information processing circumstances • Reasons for current system design • Rules for processing data 7.10

11. Analyzing Procedures and Other Documents • Four types of useful documents • Written work procedure for an individual or a work group • Describes how a job is performed • Includes data and information used and created in the process of performing the job or task • Formal systems: official way a system works as described in the organizational documentation. • Informal system: the way a system actually works • Business form • Explicitly indicate what data flow in or out of a system and which are necessary for the system to work • Report generated by current systems • Enables the analyst to work backwards from the report to the data that generated it – company’s performance is past years • Description of current information system • If the current system is computer based 7.11

12. Modern Methods for Determining Requirements • Joint Application Design (JAD) • Similar to group interview as it brings together key users, managers and systems analysts • Purpose: collect system requirements simultaneously from key people • Particular structure of roles and agenda is followed and analysts control the sequence of questions answered by users • Conducted off-site to keep participants away from distractions • may last from four hours to an entire week and may consist of many weeks • Prototyping • Repetitive process • Rudimentary version of system is built • Replaces or augments SDLC • Goal: to develop concrete specifications for ultimate system 4.12

13. Joint Application Design (JAD) • Participants • Session Leader – organizes and runs the JAD • Users – key users of the current system • Managers of the workgroups who use the current system • Sponsor – needed to cover expenses • Systems Analysts – to learn from users and managers • Scribe – takes notes • IS Staff – other IS staff like programmers, database analysts JAD sessions are usually held in special-purpose rooms where participants sit in a horse-shoe shaped tables. rooms have whiteboards, audio-visual tools like overhead projectors, flip charts, transparencies 4.13

14. Joint Application Design (JAD) • End Result • Documentation detailing existing system • Features of proposed system • CASE Tools During JAD • Upper CASE tools are used • Enables analysts to enter system models directly into CASE during the JAD session • Screen designs and prototyping can be done during JAD and shown to users 4.14

15. Prototyping • Quickly converts requirements to working version of system • Once the user sees requirements converted to system, will ask for modifications or will generate additional requests • Most useful when: • User requests are not clear • Few users are involved in the system • Designs are complex and require concrete form • History of communication problems between analysts and users • Tools are readily available to build prototype • Drawbacks • Tendency to avoid formal documentation • Difficult to adapt to more general user audience • Sharing data with other systems is often not considered • Systems Development Life Cycle (SDLC) checks are often bypassed 7.15