Analysis Chapter 4 Determining System Requirements The purpose

Analysis Chapter 4 Determining System Requirements 系統分析的目的 The purpose of analysis is to determine what information and information processing services are needed to support selected objectives and functions of the organization. 系統分析步驟 Requirements determination (fact-finding activity) how employees now perform, and how they will need to perform their jobs in order to meet future business conditions. Requirements structuring Process, Logic and timing, Data Specification Alternative generation & selection Design strategy

Analysis Chapter 4 Determining System Requirements

Analysis Chapter 4 Determining System Requirements • The Process of Determining Requirements 取得發展新系統的許可 調查(investigation) 的過程 收集資訊 Users of current system Observing users Reports Forms Documented system requirements

Analysis Chapter 4 Determining System Requirements • Characteristics for gathering requirements – Impertinence • Question everything – Impartiality (公平性) • Find the best organizational solution – Relaxation of constraints – Attention to detail – Reframing • View the organization in new ways

Analysis Chapter 4 Determining System Requirements • 傳統定義系統需求的方法 –Individual interview –Survey people via questionnaires –Interview group of people –Observe workers at selected time –Study business documents

Analysis Chapter 4 Determining System Requirements • Interviewing and Listening Guidelines for effective interviewing Typical interview guide or checklist, 事先的準備 花時間，較困難Summarize Choosing interview questions Open-ended questions - Questions in interviews and on questionnaires that have not pre-specified answers Closed-ended questions - ask those responding to choose from among a set of specified responses

Analysis Chapter 4 Determining System Requirements • Interviewing and Listening Guidelines • Plan – Checklist – Appointment • Be neutral – avoid asking leading question • Listen • Seek a diverse view – interview a wide range of people

Analysis Chapter 4 Determining System Requirements • Interview Guidelines Do not phrase a question in a way that implies a right or wrong answer Listen very carefully to what is being said Once the interview is over, go back to your office and type up your notes within 48 hours. Be careful during the interview not to set expectations about the new or replacement system unless you are sure these features will be part of the delivered system Seek a variety of perspectives from the interview (Users, managers, superiors, information systems staff)

Analysis Chapter 4 Determining System Requirements • Open Interview vs. Structured Interview 問題標準化 SA 依其現有了解知識提出簡短敘述 使用者針對主題作深度分析 對某主題有初步了解就可進行另一主題訪談

Analysis Chapter 4 Determining System Requirements • Administering Questionnaires (問卷調查) - Questionnaires are not as expensive to administer per respondent. In addition, questionnaires have the advantage of gathering information from many people in a relatively short time and of being less biased in the interpretation of their results.

Analysis Chapter 4 Determining System Requirements • Choosing Questionnaire Respondents - 四大方法 有動機有意願者 ? Those convenient to sample Combine ? A random group 符合某特定條件者 ? A purposeful sample ? A stratified sample Random 選取某一特定層次人員

Analysis Chapter 4 Determining System Requirements • Designing Questionnaires 較 prefer, 易回答, 問題明確 ? Closed-ended + Open-ended question 避免不確定性 ? Extremely clear in meaning and logical in sequence - Pretest (Example) ? very specific purpose than general information gathering 現有系統的滿意度, 那個功能是最需要的, . . .

Analysis Chapter 4 Determining System Requirements • Example: 您的電腦檔案多久備份一次 (a) 經常 (b) 有時 (c) 不常 (d) 不曾

Analysis Chapter 4 Determining System Requirements • Choosing Between Interviews & Questionnaire • Comparison • 系統複雜度與對其了解的程度

Analysis Chapter 4 Determining System Requirements • Interviewing Groups One drawback to using interviews and questionnaire 1 A series interviews inconsistent information follow-up call or interview Group Interview (Interview several key people at once) Difficult to schedule video conferences (phone)

Analysis Chapter 4 Determining System Requirements • Directly Observing Users §People, however, are not always very reliable informants. §Serves as a good method to supplement interviews §Often difficult to obtain unbiased data - People often work differently when being observed 標準作業與內容 落插 實際作業與內容

Analysis Chapter 4 Determining System Requirements • Analyzing Procedures and Other Documents • Types of information to be discovered: – – – – Problems with existing system Opportunity to meet new need Organizational direction Names of key individuals Values of organization Special information processing circumstances Rules for processing data

Analysis Chapter 4 Determining System Requirements

Analysis Chapter 4 Determining System Requirements • Modern Information Gethering Techniques • Joint Application Design (JAD) – Brings together key users, managers and systems analysts – Purpose: collect system requirements simultaneously from key people – Conducted off-site • Prototyping – Repetitive process – Rudimentary (初步的) version of system is built – Replaces or augments SDLC – Goal: to develop concrete specifications for ultimate system

Analysis Chapter 4 Determining System Requirements

Analysis Chapter 4 Determining System Requirements Joint Application Design (JAD) • Participants – Session Leader – Users – Managers – Sponsor – Systems Analysts – Scribe – IS Staff (Besides system analysts)

Analysis Chapter 4 Determining System Requirements Joint Application Design (JAD) • End Result – Documentation detailing existing system – Features of proposed system

Analysis Chapter 4 Determining System Requirements 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

Analysis Chapter 4 Determining System Requirements Prototyping • 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

Analysis Chapter 4 Determining System Requirements Radical(根本的) Methods – BPR, Business Process Reengineering § Search for and implementation of radical change in business processes to achieve breakthrough improvements in products and services § Goals ü Reorganize complete flow of data in major sections of an organization ü Eliminate unnecessary steps ü Combine steps ü Become more responsive to future change

Analysis Chapter 4 Determining System Requirements Identification of processes to reengineer Customer focus Identify Key Business Process Identify specific activities Disruptive Technologies How important is the activity to delivering an outcome? How feasible is changing the activity? How dysfunctional(不正常的) is the activity?

Analysis Chapter 4 Determining System Requirements Disruptive technologies Technologies that enable the breaking of long-held business rules that inhibit organizations from making radical business changes n

Analysis Chapter 4 Determining System Requirements