Lecture Systems analysis and design with UML (3 e) Chapter 4 Requirements determination

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Lecture Systems analysis and design with UML (3 e)  Chapter 4 Requirements determination

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This chapter begins by presenting the requirements definition, a document that lists the new system’s capabilities. It then describes how to analyze requirements using business process automation, business process improvement, and business process reengineering techniques and how to gather requirements using interviews, JAD sessions, questionnaires, document analysis, and observation.

Chapter 4: Requirements Determination PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Objectives • Understand how to create a requirements definition • Become familiar with requirements analysis techniques • Understand when to use each requirements analysis technique • Understand how to gather requirements using interviews, JAD sessions, questionnaires, document analysis, and observation • Understand when to use each requirementsgathering technique PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved The SDLC and Requirements • The SDLC transforms the existing (as is) system into the proposed (to be) system • Requirements determination step is the single most critical step of the entire SDLC – Studies show that more than half of all system failures are due to problems with requirements PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved REQUIREMENTS DETERMINATION PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Defining a Requirement • A statement of what the system must or what characteristic it must have • During analysis, requirements are written from the perspective of the businessperson • Two kinds of requirements: – Functional – Nonfunctional PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Nonfunctional Requirements PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Requirements Definition Report • • • • • • • • Correct Unambiguous Complete Consistent Verifiable Modifiable Traceable Ranked for importance PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved A Bad Requirement Initial Initial Specification: Specification: Software Software will will not not be be loaded loaded from from unknown unknown sources sources onto onto the the system system without without first first having having the the software software tested tested and and approved approved Critique: Critique: •• Ambiguous Ambiguous –– ifif the the software software is is tested tested and and approved, approved, can can itit be be loaded loaded from from unknown unknown sources? sources? •• (not) (not) Testable Testable –– itit is is stated stated as as aa negative negative requirement requirement making making itit difficult difficult to to verify verify •• (not) (not) Traceable Traceable –– aa unique unique identifier identifier is is missing missing Re-specification: Re-specification: 3.4.5.2 3.4.5.2 Software Software shall shall be be loaded loaded onto onto the the operational operational system system only only after after itit has has been been tested tested and and approved approved PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Determining RequirementsRequirements are best determined by systems analysts and business people together • Techniques available to the systems analyst: – Interviews – Questionnaires – Observation – Joint application development (JAD) – Document analysis PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved REQUIREMENTS ANALYSIS STRATEGIES PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Post-Interview PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Joint Application Development • Allows the project team, users, and management to work together to identify requirements for the system • Often the most useful method for collecting information from users • Key roles: – Facilitator – Scribe PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved JAD Meeting Room JPEG Figure 5-5 Goes Here PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved The JAD Session • • • • Tend to last to 10 days over a three week period Prepare questions as with interviews Formal agenda and ground rules Facilitator activities – Keep session on track – Help with technical terms and jargon – Record group input – Help resolve issues • Post-session follow-up PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Managing Problems in JAD Sessions • • • • • • • • Reducing domination Encouraging non-contributors Side discussions Agenda merry-go-round Violent agreement Unresolved conflict True conflict Use humor PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Questionnaires • A set of written questions used to obtain information from individuals • Often used for large numbers of people from whom information and opinions are needed • Common technique with systems intended for use outside the organization • Response rates vary, but typically are significantly less than 50% PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Questionnaire Steps • Selecting participants – Using samples of the population • Designing the questionnaire – Careful question selection • Administering the questionnaire – Working to get good response rate • Questionnaire follow-up – Send results to participants PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Good Questionnaire Design • Begin with non-threatening and interesting questions • Group items into logically coherent sections • No important items at the very end • Do not crowd a page with too many items • Avoid abbreviations • Avoid biased or suggestive items or terms • Number questions to avoid confusion • Pretest to identify confusing questions • Provide anonymity to respondents PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Document Analysis • Provides clues about existing “as-is” system • Typical documents – Forms – Reports – Policy manuals • Look for user additions to forms • Look for unused form elements PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Observation • Users/managers often don’t remember everything they • Checks validity of information gathered other ways • Behaviors change when people are watched • Careful not to ignore periodic activities – Weekly … Monthly … Annual PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Other Techniques • Throw-away prototyping • Role playing CRC cards with use cases • Mind/concept mapping PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Selecting Appropriate Techniques PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved THE SYSTEM PROPOSAL PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved The System Proposal • The result of the planning and analysis phases • Typically includes: – Executive summary – System request – Work plan – Feasibility analysisRequirements definition – Evolving system models PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Summary • • • • Requirements determination Requirements analysis strategies Requirements-gathering techniques The system proposal PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved ... Understand how to create a requirements definition • Become familiar with requirements analysis techniques • Understand when to use each requirements analysis technique • Understand how to gather requirements. .. document analysis, and observation • Understand when to use each requirementsgathering technique PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd... Wixom, & Tegarden Systems Analysis and Design with UML, 3rd Edition Copyright © 2009 John Wiley & Sons, Inc All rights reserved Good Questionnaire Design • Begin with non-threatening and interesting

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Mục lục

  • Chapter 4: Requirements Determination

  • Objectives

  • The SDLC and Requirements

  • Requirements Determination

  • Defining a Requirement

  • Nonfunctional Requirements

  • Requirements Definition Report

  • A Bad Requirement

  • Determining Requirements

  • Requirements Analysis Strategies

  • Slide 11

  • Business Process Automation

  • Problem Analysis

  • Root Cause Analysis

  • Root Cause Analysis Example

  • Business Process Improvement

  • Business Process Reengineering

  • Selecting the Appropriate Strategies

  • Requirements-Gathering Techniques

  • Five Basic Steps of Interviews

  • Selecting Interviewees

  • Interviewing Strategies

  • Post-Interview

  • Joint Application Development

  • JAD Meeting Room

  • The JAD Session

  • Managing Problems in JAD Sessions

  • Questionnaires

  • Questionnaire Steps

  • Good Questionnaire Design

  • Document Analysis

  • Observation

  • Other Techniques

  • Selecting Appropriate Techniques

  • The System Proposal

  • Slide 36

  • Summary

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