An Introduction to Object-Oriented Systems Analysis and Design with UML and the Unified Process McGraw-Hill, 2004 Stephen R. Schach [email protected] 4Chapter OverviewChapter Overview (contd)Determining the Client’s NeedsDetermining the Client’s Needs (contd)Slide 7Overview of the Requirements WorkflowFlowchart of the Requirements WorkflowDefinitionsUnderstanding the DomainInitial Understanding: Osbert Oglesby Case StudyGlossary: Osbert Oglesby Case StudyBusiness ModelInterviewingInterviewing (contd)Slide 17Other Information Gathering TechniquesOther Information Gathering Techniques (contd)Use CasesUse Cases (contd)Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Init. Business Model: Osbert Oglesby Case StudySlide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Initial RequirementsInitial Requirements (contd)Slide 42Initial Requirements: Osbert Oglesby Case StudyInitial Requirements: Osbert OglesbyInitial Requirements: Osbert Oglesby (contd)Slide 46Slide 47Requirements Workflow: Osbert OglesbyAttributes: Osbert Oglesby Case StudySlide 50Maximum Price for a MasterpieceMaximum Price for a MasterworkMaximum Price for an Other PaintingCoefficient of Similarity: Osbert OglesbyCoefficient of Similarity: Osbert Oglesby (contd)Fashionability Coefficients: Osbert OglesbyAuction Data: Osbert Oglesby Case StudyUpdated Use Cases : Osbert Oglesby Case StudySlide 59Reports for the Osbert Oglesby Case StudyReport of Purchases during the Past YearReport of Sales during the Past YearReport of Trends during the Past YearUpdated Use-Case Description: Produce a ReportIt Ain’t Over Till it’s OverUse-Case Modify a Fashionability CoefficientSecond Iteration of Use-Case DiagramAnalysis of Req. Workflow: Osbert OglesbySlide 4.1Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. An Introduction toObject-Oriented Systems Analysis and Design with UML and the Unified Process McGraw-Hill, 2004Stephen R. [email protected] 4.2Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. CHAPTER 4THE REQUIREMENTS WORKFLOW ISlide 4.3Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter OverviewDetermining What the Client NeedsOverview of the Requirements WorkflowUnderstanding the DomainInitial Understanding of the Domain: Osbert Oglesby Case StudyBusiness ModelInterviewingOther techniquesSlide 4.4Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter Overview (contd)Use CasesInitial Business Model: Osbert Oglesby Case StudyInitial RequirementsInitial Requirements: Osbert Oglesby Case StudyContinuing the Requirements Workflow: Osbert Oglesby Case StudyIt Ain’t Over Till it’s OverSlide 4.5Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Determining the Client’s NeedsConsider the requirements workflowThe primary task of the systems analyst is to determine what the client needs–This may not be what the client says that he or she wantsInformation systems are complex–Clients therefore often ask for the wrong information systemSlide 4.6Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Determining the Client’s Needs (contd)It is hard for a systems analyst to visualize an information system and its functionality–The problem is far worse for the clientA skilled systems analyst is needed to elicit the appropriate information from the clientThe client is the only source of this informationSlide 4.7Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Determining the Client’s Needs (contd)The solution:–Obtain initial information from the client –Use this initial information as input to the Unified Process–Follow the steps of the Unified Process to determine the client’s real needsSlide 4.8Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Overview of the Requirements WorkflowFirst, gain an understanding of the application domain (domain, for short)–(The specific business environment in which the information system is to operate)Second, build a business model–Use UML to describe the client’s business processesThird, use the business model to determine the client’s requirementsThen iterate (“repeat”) the above stepsSlide 4.9Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Flowchart of the Requirements WorkflowSlide 4.10Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. DefinitionsDiscovering the client’s requirements–Requirements elicitation (or requirements capture)–Methods include interviews and surveysRefining and extending the initial requirements –Requirements analysisSlide 4.11Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Understanding the DomainEvery member of the development team must become fully familiar application domain–Correct terminology is essentialWe must build a glossary–That is, a list of technical words used in the domain, and their meaningSlide 4.12Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Initial Understanding: Osbert Oglesby Case StudyOsbert Oglesby, Art Dealer, needs an information system to assist him in buying and selling paintingsObtaining domain knowledge is the first stepOsbert is interviewed to obtain the relevant informationThis information is put into a glossary (see next slide)Slide 4.13Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Glossary: Osbert Oglesby Case StudySlide 4.14Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Business ModelA business model is a description of the business processes of an organizationThe business model gives an understanding of the client’s business as a whole–This knowledge is essential for advising the client regarding computerizationThe systems analyst needs to obtain a detailed understanding of the various business processes– Different techniques are used, primarily interviewingSlide 4.15Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. InterviewingThe requirements team meet with the client and users to extract all relevant informationSlide 4.16Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Interviewing (contd)There are