Hei-Lesson_06.ppt

1、InformationSystem Analysis&Design Methods,计算机科学与工程学院,Xinhong HEI Lei WANG ADD: Rd. South of Jinhua 5, 710048, Xian TEL: 0086 29 8231 2196 1010 FAX: 0086 29 8231 2456 Email: WEB: 0/sysana/index.aspx,计算机科学与工程学院,Lesson Review,Statement of Work (SOW) Describes what project will delive

2、r Lists all work to be performed Baseline Project Plan (BPP) Created during project initiation and planning Contains: Introduction, High-Level description of system, Outline of feasibility and Overview of Management Issues Feasibility Economic Operational Technical Schedule Legal Contractual Politic

3、al Time value of money (TVM) The process of comparing present cash outlays to future expected returns.,Lesson Six,Determining System Requirements,计算机科学与工程学院,计算机科学与工程学院,Objectives,What is an interview? and what is it like? How about using questionnaires to determine system requirements Explain advant

4、ages and disadvantages of observing workers and analyzing business documents to determine requirements How about Joint Application Design (JAD) and Prototyping Discuss appropriate methods to elicit system requests Explain Business Process Re-engineering (BPR),计算机科学与工程学院,Performing Requirements Deter

5、mination,Gather information on what system should do from many sources Users Reports Forms Procedures,计算机科学与工程学院,Performing Requirements Determination,Characteristics for gathering requirements Impertinence Question everything Impartiality Find the best organizational solution Relaxation of constrai

6、nts Reframing View the organization in new ways Attention to detail,计算机科学与工程学院,Deliverables and Outcomes,Understanding of organizational components Business objective Information needs Rules of data processing Key events,计算机科学与工程学院,Traditional Methods for Determining Requirements,计算机科学与工程学院,Traditio

7、nal Methods for Determining Requirements: Preparing for the Interview,Interviewing and Listening Gather facts, opinions and speculations Observe body language and emotions Guidelines Plan Checklist Appointment Be neutral Listen and record Review notes Seek a diverse view,计算机科学与工程学院,Plan the Intervie

8、w Checklist,计算机科学与工程学院,Traditional Methods for Determining Requirements: Interviewing and Listening,Interview Questions Close-Ended Respondent is asked to choose from a set of specified responses Open-Ended No pre-specified answers,计算机科学与工程学院,Traditional Methods for Determining Requirements: Conduct

9、ing the Interview,Observe body language and emotions Be neutral Listen and record Do not raise expectations about future system Seek a diverse view Review notes,计算机科学与工程学院,Traditional Methods for Determining Requirements: Administering Questionnaires,More cost-effective than interviews Choosing resp

10、ondents Should be representative of all users Types of samples Random sample Purposeful sample Stratified sample Check for non-response bias Design Mostly closed-ended questions Can be administered over the phone or in person,计算机科学与工程学院,Traditional Methods for Determining Requirements: Formulating Q

11、uestions,How often do you back up your computer files Frequently Sometimes Hardly at all Never,How often do you back up the computer files on the hard disk on the PC in your office? Frequently (at least once per week) Sometimes (from one to three times per month) Hardly at all (once per month or les

12、s) Never,计算机科学与工程学院,Traditional Methods for Determining Requirements: Comparing Interviews and Questionnaires,计算机科学与工程学院,Traditional Methods for Determining Requirements: Directly Observing Users,Serves as a good method to supplement interviews Often difficult to obtain unbiased data People often wo

13、rk differently when being observed,计算机科学与工程学院,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 circumstanc

14、es Rules for processing data,计算机科学与工程学院,Analyzing Procedures and Other Documents: Company Forms,计算机科学与工程学院,Analyzing Procedures and Other Documents: Company Reports,计算机科学与工程学院,Traditional Methods for Determining Requirements: Comparing Observation and Document Analysis,计算机科学与工程学院,Modern Methods for

15、Determining Requirements,Prototyping Joint Application Design,计算机科学与工程学院,Modern Methods for Determining Requirements: Prototyping,Repetitive process Rudimentary version of system is built Replaces or augments SDLC Goal: to develop concrete specifications for ultimate system Quickly converts requirem

16、ents to working version of system Once the user sees requirements converted to system, will ask for modifications or will generate additional requests,计算机科学与工程学院,Modern Methods for Determining Requirements: Prototyping,Most useful when: User requests are not clear Few users are involved in the syste

17、m 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

18、considered Systems Development Life Cycle (SDLC) checks are often bypassed,计算机科学与工程学院,Modern Methods for Determining Requirements: JAD,Joint Application Design (JAD) Brings together key people Purpose: collect system requirements simultaneously from key people Often conducted off-site Participants I

19、nclude: Session Leader, Users, Managers, Sponsor, Systems Analysts, Scribe, IS Staff End Result Documentation detailing existing system Features of proposed system,计算机科学与工程学院,计算机科学与工程学院,A JAD Workshop,May last several days Lots of pre-planning Retreat Atmosphere No more than 15 people Can technology

20、 help?,计算机科学与工程学院,Business Process Reengineering,Business Process Reengineering (BPR) Search for, and implementation of, radical change in business processes to achieve breakthrough improvements in products and services Goals Reorganize complete flow of data in major sections of an organization Elim

21、inate unnecessary steps Combine steps Become more responsive to future change Identification of processes to reengineer Key business processes Set of activities designed to produce specific output for a particular customer or market Focused on customers and outcome Same techniques are used as were used for requirements determination,计算机科学与工程学院,BPR: Disruptive Technologies,Disruptive Technologies Technologies that enable the b