Lecture Objectives. Example system. What data to gather? What data to gather? CSE Information Systems 1

Transcription

1 CSE Information Systems 1 Lecture Objectives DATA GATHERING FOR INFORMATION SYSTEMS DEVELOPMENT to be aware of various methods for data gathering ( fact-finding ) in respect of information system development to understand the usefulness and suitability of various data gathering methods for particular problem situations Example system Data gathering in systems development Data gathering is a major task of systems analysis. Easy Go Hotel Systems analysis involves: Understanding and describing how the current system functions Determining what users would like their new system to do (user requirements) Necessary for system analysts to collect information about current and future situations, problems,opportunities, constraints The business or organisation: Data about the nature of the business and its market and business environment Data about business goals and objectives that dictate what and how work is done Data about organisational structure: major functions, departments etc Data about major business subsystems and how they interact Data about business policies and guidelines Users of the system: Roles and responsibilities Reporting structures Job specifications and actual tasks performed Information needed to do their jobs Formal and informal communication and workflow channels

2 Users of the system: Data about roles and responsibilities Data about reporting structures Job specifications and data about actual tasks performed Data about information needed to do their jobs Data about formal and informal communication and workflow channels The existing system: Data about tasks and workflow: functions, processes, sequence of processes, methods and procedures, inputs, outputs Data about the data (definition, volumes, size etc.) Data about interactions with other systems Data about work volumes and processing cycles Data about performance standards and criteria Data about control mechanisms: e.g security, accuracy Data about problems: e.g. efficiency, information The new system: Data about system requirement: a need or desire to be met by a proposed system Data about both functional requirements (processes and functionality) and non-functional requirements (security, performance, service etc.) Data about constraints e.g. existing technology Data about interactions with other systems Data about relationship to existing system/s Sources of data Users and other stakeholders Documents about the system Documents about the organisation Documents and data used within the existing system Transactions within existing system External sources Sources of data Users System sponsor/owner: overall project objectives Managers: high level, broad view of existing system and requirements End-users: detailed, operational level view of existing system and requirements Technical staff: technology capaabilities, limitations etc. External stakeholders: e.g. customers Sources of data Documents about the system and organisation: Organisation charts Policy manuals Business reports: financial, annual etc. Jobs, procedure, operations manuals Training manuals Existing system documentation Internal reports relating to the system

3 Sources of data Documents and data used within the existing system: Files, databases, programs, forms, reports Informal: Memos, bulletin boards, files External sources: Other organisations systems Hardware & software vendors Business & industry publications What data gathering methods? Interviews Questionnaires Observation Sampling documents and transactions Research and site visits Interviews The interview strategy Generally the most important and widely-used method for data gathering May be formal/structured (specific questions) or informal/unstructured (general goal or purpose) Need an interview strategy for the entire interviewing process Establish general objectives and guidelines for the entire interviewing process: e.g. information to be obtained, sources, formats, documenting, analysis Identify the users to interview: Ensure all key people are included Need an interview plan or guide for each interview The interview strategy Determine the sequence of interviews: Co-ordinate the interviewing process: Compare results, select follow ups etc. Need individual interview plans Need to consider: Who has the information you need? Where to conduct the interview? When is the best time to interview? How should the interview progress? The individual interview Before the interview: Arrange time and place, necessary materials, inform interviewee of interview purpose Conduct the interview After the interview: Write an interview report Review this with the interviewee at a follow up interview

4 The interview structure Preliminaries: Introduction, purpose, environment and procedures e.g. permission to tape Body : Define what you already believe to be true and confirm this, explore points & issues further, new areas (questions) Conclusion: Summarise and confirm your findings Schedule a follow up interview The interview plan Interview plans: Decide on interview structure Determine content of questions Decide on question types See Whitten et al (2001),Figure 6.5 pp 233 for a sample interview guide. Interviews: types of questions Closed: how many transactions per day? Limits available responses Open: tell me about.. Leaves options open for interviewee Probe: tell me more about the problem with the. To clarify and expand Mirror: From what you said, I understand that. To confirm what was said etc. Interviews: types of questions Avoid long, complex, or double-barrelled questions: what decisions are made during this process and how do you make them? Avoid leading questions; you don t need the customer number on this report, do you? Avoid loaded questions: when did you first discover the mistake? i.e. how long have you known and done nothing? Interviews: advantages obtain extensive, complex detailed information get insights and opinions discover informal procedures flexible e.g. explore issues further or new issues establish rapport with interviewee and understand their attitudes reveal the politics of the system environment information is revealed both by the spoken word and by the interviewee s body language guaranteed response Interviews: Disadvantages Time-consuming Costly Danger of bias More difficult to tabulate and analyse results e.g. to obtain an overall picture Success in interviewing depends on the interpersonal skills of the interviewer

5 Questionnaires A structured method of data gathering in which written questions/comments are provided for the participants to respond to in written form The questionnaire can take many forms - write comments/ select from a list of possible responses/ mark on a scale May permit either quantitative or qualitative data (mark out of 10/grade from good to bad) Usually involves no direct contact between data gatherer and respondents Questionnaires Useful when small amounts of data are required from a large number of people For geographically dispersed respondents Types of questions: Open-ended (free format) Fill-in-the-blank Multiple choice Rating Ranking Designing questionnaires What facts and opinions to be collected Who to sample and sample size Types of questions and wording (precise, accurate, unambiguous) How to administer e.g. paper, online, mail out etc. Format and layout (grouping, crosschecks etc.) Test on small sample of respondents How completed questionnaires will be returned and collated How analysis of the data will be carried out Questionnaires Useful for: Obtaining simple opinions, facts Quantifying what was found in interviews Identifying issues before interviewing Determining extent of problems Not useful for detailed or complex information or exploring issues in depth Can supplement other methods Questionnaires: advantages most economical method for gathering data from large numbers of people quick and easy to administer results can be tabulated rapidly and analysed readily allow respondents to be anonymous gives respondents time to reflect on answers respondents complete in their own time Questionnaires: disadvantages difficult to construct effective questionnaires specific and limited amounts of information possible low return rates possible bias and misinterpretation cannot probe issues further (inflexible) cannot clarify vague or incomplete answers lack non-verbal communication

6 Observation observing the actual processes of a system need to prepare beforehand, and report on data collected gain first hand knowledge of current system s operations clarify other information collected understand complex procedures inexpensive behaviour distortions may affect reliability unrepresentative samples affect reliability Sampling of documents and transactions Sampling: collecting a representative sample of documents, forms, transactions Useful for specific information e.g. transaction volumes and types, file sizes Useful where large volumes exist Information about existing system operations Representative samples must be selected: determine sample size, appropriate range, avoid bias Research and site visits Other data gathering methods Most problems not unique: learn from experiences of other organisations Professional societies can provide contacts for site visits Computer trade journals and magazines and the internet can be sources for research into the problem/s e.g. do appropriate software packages exist? Other modern methods used: Discovery prototyping JAD (Joint Application Development) sessions Focus groups A data gathering strategy Data gathering must be carefully planned in order to make the most of the time and resources available: Information sources Data gathering methods Recording and documentation methods Data analysis methods Procedures for reviewing results with management and users A data gathering strategy E.g. a top down approach: Initial interviews with management to determine major system activities and data Document and verify this Expand major system component descriptions into detailed descriptions: Interview operational users, sampling, questionnaires, observation etc Document and verify this Repeat these last two steps as necessary Review findings with management

7 A data gathering strategy Data gathering in practice Consider costs: allow for time and resources required for initial and ongoing information gathering Use the least expensive methods first Plan how to check the validity of data: Cross checking between groups, methods Evaluate data for inconsistencies Ask further questions Plan documentation of data e.g. records of interviews etc. data dictionary, system models Completeness? Accuracy? Objectivity? Biases? Stability? Representative? Finished? References WHITTEN, J.L., BENTLEY, L.D. and DITTMAN, K.C. (2001) 5th ed., Systems Analysis and Design Methods, Irwin/McGraw-HilI, New York, NY. Chapter 6 HOFFER, J.A., GEORGE, J.F. and VALACICH (1999) 2nd ed., Modern Systems Analysis and Design, Benjamin/Cummings, Massachusetts. Chapter 7 DWYER, J. (1997) The Business Communication Handbook (4 th edition) Prentice-Hall, New York, N.Y. Chapter 5