An Introduction to Object-Oriented Systems Analysis and Design with UML and the Unified Process McGraw-Hill, 2004 Stephen R. Schach [email protected] 1Chapter OverviewChapter Overview (contd)Jethro’s Boot EmporiumDefinitionsCustom Information SystemCOTS SoftwareTraditional Information System DevelopmentOverview of the Traditional PhasesOverview of the Traditional Phases (contd)Why There Is No Planning PhaseWhy There Is No Planning Phase (contd)Why There is No Testing PhaseWhy There Is No Documentation PhaseSystems Analysis and DesignMaintenanceThe Financial Implications of MaintenanceMaintenance ActivitiesSoftware OrganizationsSlide 21Typical Information Systems DivisionInformation Technology ProfessionalsInformation Technology Professionals (contd)Essential Systems Analyst SkillsEthical IssuesSlide 1.1Copyright © 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] 1.2Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. CHAPTER 1INTRODUCTION TO INFORMATION SYSTEMSSlide 1.3Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter OverviewCategories of Information SystemsTraditional Information System Development–The Requirements Phase–The Analysis Phase–The Design Phase–The Implementation Phase–The Maintenance Phase–RetirementSlide 1.4Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter Overview (contd)Why There Is No Planning PhaseWhy There Is No Testing PhaseWhy There Is No Documentation PhaseSystems Analysis and DesignMaintenanceInformation Technology ProfessionalsSlide 1.5Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Jethro’s Boot EmporiumAutomated reordering systemJethro’s formula for predicting future trendsThe formula works perfectly …… at firstSlide 1.6Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. DefinitionsArtifact–ComponentSystem–Set of artifacts that achieve some outcomeInformation system–System that achieves a business outcomeComputerized information system–COTS (commercial off-the-shelf) package–Custom information systemSlide 1.7Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Custom Information SystemStakeholders–Client–Users–DevelopersSlide 1.8Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. COTS SoftwareShrinkwareClickwareStakeholders–Users–DevelopersEnterprise Resource Planning (ERP) system–Examples: PeopleSoft, SAPSlide 1.9Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Traditional Information System DevelopmentInformation system life cycle–The way that software is constructedSix traditional phasesSlide 1.10Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Overview of the Traditional PhasesRequirements phase–Find the client’s requirements–Draw up the requirements documentAnalysis phase–Draw up the specification document–Draw up the project management planDesign phase–Determine the modules–Determine algorithms and data structures for each moduleSlide 1.11Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Overview of the Traditional Phases (contd)Implementation phase–Translate the modules into a programming language–Integrate the modulesMaintenance phase–Modify the system»Remove any remaining faults »Extend the system in some wayRetirement–The system no longer provides a useful serviceSlide 1.12Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Why There Is No Planning PhaseWe cannot plan until we have accurate, detailed informationThere are three types of planning activities:–There is preliminary planning at the start of the project–The project management plan is drawn up after the specifications have been approved by the client–Management monitor the plan all through the projectSlide 1.13Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Why There Is No Planning Phase (contd)Planning activities are carried out all through the life cycle There is no separate planning phaseSlide 1.14Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Why There is No Testing PhaseChecking the information system just before delivery is much too lateAn information system must be checked continually  There is no separate testing phaseSlide 1.15Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Why There Is No Documentation PhaseThe documentation must be complete, correct, and up to date at all times–Personnel turnover in the information system industry–Performing a phase requires the documentation from the previous phaseTesting activities require documentationMaintenance activities require documentation There is no separate documentation phaseSlide 1.16Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Systems Analysis and DesignThe word analysis is used in two different ways:–Analysis: Phase 2–Systems analysis: Phases 1 and 2The term systems analyst is also used in two different ways–Responsible for Phases 1 and 2; or–Responsible for Phases 1, 2, and 3The second usage is more common–That is the way systems analyst is used in this bookSlide 1.17Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. MaintenanceBad information systems are thrown awayGood information systems are maintained for many yearsSlide 1.18Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. The Financial Implications of MaintenanceFor very $1 spent on development, at least $2 is spent on maintenanceSlide 1.19Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Maintenance Activities There are three main maintenance activities:Corrective maintenance–Fixing faultsPerfective maintenance –Adding functionalityAdoptive maintenance–Making changes because the environment changes–(Enhancement: Corrective + Perfective maintenance)Slide 1.20Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Software OrganizationsSoftware–Computer