Presentation on theme: "Chapter 1 The Systems Development Environment"— Presentation transcript:
1 Chapter 1 The Systems Development Environment Modern Systems Analysis and Design Fourth Edition Jeffrey A. Hoffer Joey F. George Joseph S. ValacichChapter 1The Systems Development Environment
2 Learning Objectives Define information systems analysis and design. Describe the different types of information systems.Describe the information Systems Development Life Cycle (SDLC).Explain Rapid Application Development (RAD), prototyping, Joint Application Development (JAD), and Computer Aided Software Engineering (CASE).Describe agile methodologies and eXtreme programming.Explain Object Oriented Analysis and Design and the Rational Unified Process (RUP).
3 Introduction Information Systems Analysis and Design Goal: Complex organizational process whereby computer-based information systems are developed and maintainedGoal:To develop Applications SoftwareStakeholders:UsersSystems Analysts
4 IntroductionVarious software engineering processes have been developed to assist in analysis and design; these include:MethodologiesComprehensive, multi-step approaches to systems developmentTechniquesProcesses that are followed to ensure that work is well thought-out, complete and comprehensible to others on the project teamToolsComputer programs to assist in application of techniques to the analysis and design process
5 A Modern Approach to Systems Analysis and Design 1950s: focus on efficient automation of existing processes1960s: advent of 3GL, faster and more reliable computers1970s: system development becomes more like an engineering discipline1980s: major breakthrough with 4GL, CASE tools, object oriented methods1990s: focus on system integration, GUI applications, client/server platforms, InternetThe new century: Web application development, wireless PDAs, component-based applications
6 Types of Information Systems you might work on Transaction Processing Systems (TPS)Automate handling of data about business activities (transactions)Process orientationManagement Information Systems (MIS)Converts raw data from transaction processing system into meaningful formData orientationDecision Support Systems (DSS)Designed to help decision makersProvides interactive environment for decision makingInvolves data warehouses, executive information systems (EIS)Database, model base, user dialogueEach of these systems could be implemented in either a traditional client/server or net-enabled environment
7 Types of Information Systems and Systems Development Methods Each of these systems could be implemented in either a traditional client/server or net-enabled environment
8 What’s important in application development? Three key components of an IS application are…The DataThe way Data FlowsThe Processing Logic to manipulate data and produce information for decision making
9 Systems Development Life Cycle (SDLC) Traditional methodology for developing, maintaining, and replacing information systemsPhases in SDLC include…PlanningAnalysisDesignImplementationMaintenance
11 SDLC Planning PhaseIdentify, analyze, prioritize, and arrange IS needs
12 SDLC Analysis PhaseStudy and structure system requirements
13 SDLC Design PhaseLogical design: functional features described independently of computer platformConvert recommended solution to system specificationsPhysical design: logical specifications transformed to technology-specific details
14 SDLC Implementation Phase Code, test, install, and support the information system
15 SDLC Maintenance Phase Systematically repair and improve the information system
17 The Heart of the Systems Development Process Current practice combines analysis, design, and implementation into a single iterative and parallel process of activities
18 Traditional Waterfall SDLC One phase begins when another completes, little backtracking and looping
19 What are the problems with the Waterfall Approach System requirements “locked in” after being determined (can't change)Limited user involvement (only in requirements phase)Too much focus on milestone deadlines of SDLC phases to the detriment of sound development practices
20 Alternatives to Traditional Waterfall SDLC PrototypingCASE toolsJoint Application Design (JAD)Rapid Application Development (RAD)Agile MethodologieseXtreme Programming
21 Prototyping Iterative development process: Requirements quickly converted to a working systemSystem is continually revisedClose collaboration between users and analysts
22 CASE Tools Computer-Aided Software Engineering Software tools providing automated support for systems developmentProject dictionary/workbook: system description and specificationsDiagramming toolsExample products: Oracle Designer, Rational Rose
23 Joint Application Design (JAD) Structured process involving users, analysts, and managersSeveral-day intensive workgroup sessionsPurpose: to specify or review system requirements
24 Rapid Application Development (RAD) Methodology to decrease design and implementation timeInvolves: prototyping, JAD, CASE tools, and code generators
25 Agile MethodologiesMotivated by recognition of software development as fluid, unpredictable, and dynamicThree key principlesAdaptive rather than predictiveEmphasize people rather than rolesSelf-adaptive processes
26 eXtreme Programming Short, incremental development cycles Automated testsTwo-person programming teamsCoding and testing operate togetherAdvantages:Communication between developersHigh level of productivityHigh-quality code
27 Object-Oriented Analysis and Design Based on objects rather than data or processesObject: a structure encapsulating attributes and behaviors of a real-world entityObject class: a logical grouping of objects sharing the same attributes and behaviorsInheritance: hierarchical arrangement of classes enable subclasses to inherit properties of superclasses
28 Organizational Responsibilities in Systems Development Skills required to be a Successful Systems AnalystAnalyticalUnderstanding of organizationsProblem solving skillsSystem thinkingAbility to see organizations and information systems as systemsTechnicalUnderstanding of potential and limitations of technologyManagementAbility to manage projects, resources, risk and changeInterpersonalEffective written and oral communication skills
29 Organizational Responsibilities in Systems Development ProgrammersConvert specifications into instructions that the computer understandsWrite documentation and testing programsBusiness ManagersHave power to fund projects and allocate resourcesSet general requirements and constraints for projectsProject ManagerSupervises the team of IS professionals and users who are designing the ISDatabase AdministratorInvolved in design, development and maintenance of databasesNetwork and telecommunications expertsDevelop systems involving data and/or voice communicationsHuman Factors SpecialistsInvolved in training users and writing documentationInternal AuditorsEnsure that required controls are built into the system
30 Establishing Objectives for Systems Development Systems development objectives should be supportive of, and aligned with, organizational goals.There are four kinds of objectives that should be considered:Performance objectives.Cost objectives.Control objectives.Complexity objectives.
31 In conclusion, consider the following Systems Development Laws: Brook’s Law:Adding manpower to a late software project makes it later!(Frederick P Brooks Jr.)Hofstadter's Law: It always takes longer than you think, even when you take Hofstadter's Law into account.(Douglas Hofstadter)
32 Rational Unified Process (RUP) involves an iterative, incremental approach to systems development
33 Summary In this chapter you learned how to: Define information systems analysis and design.Describe the different types of information systems.Describe the information Systems Development Life Cycle (SDLC).Explain Rapid Application Development (RAD), prototyping, Joint Application Development (JAD), and Computer Aided Software Engineering (CASE).Describe agile methodologies and eXtreme programming.Explain Object Oriented Analysis and Design and the Rational Unified Process (RUP).
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