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Chapter 1 The Systems Development
Environment
© 2011 by Prentice Hall: J.A.Hoffer et.al., Modern Systems Analysis & Design, 6th Edition 2/55
Your Objects of SA&D Study
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Course Content
Fundamental of System DevelopmentSystem Development Life Cycle
System PlanningSystem AnalysisSystem DesignSystem Implementation and Maintenance
StandardSustainable System Development
Management /People
Business Driven
Methodology ICT: Internet H/W, S/W
IS
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IS: Enterprise Applications
Kaizen (for SME) ++ Overall+Quality Control
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ERP: need (customer driven) innovation using advance technologies
HRCorporate social responsibility
Financial Financial performance
OperationsOutstanding commitment to environmentFull servicesSmart convergence services (solution)
Marketing & salesExcellent customer serviceOutstanding customer serviceAdvance & extensive network deploymentFiled market leadershipNetwork depth & reliability
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Content
Information systems analysis and design (SA&D)Different types of information systemsInformation Systems Development Life Cycle (SDLC)Rapid Application Development (RAD), Prototyping, Joint Application Development (JAD), and Computer Aided Software Engineering (CASE)Agile methodologies and eXtreme programmingObject Oriented Analysis and Design and Rational Unified Process (RUP)
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1. Introduction
Information Systems Analysis and DesignComplex organizational processUsed to develop and maintain computer-based information systemsUsed by a team of business and systems professionals
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Introduction (Cont.)
An organizational approach to systems analysis and design is driven by methodologies, techniques, and tools
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Modern Approach to SA&D
1950s: efficient automation of existing processes1960s: 3GL, faster and reliable computers1970s: system development, using engineering discipline1980s: 4GL, CASE tools, object oriented methods1990s: system integration, GUI applications, client/server platforms, InternetThe new century : Web application development, wireless PDAs, component-based applications, ubiquitous technology
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Modern Approach to SA&D (Cont.)
Application SoftwareComputer software designed to support organizational functions or processes
Systems AnalystOrganizational role most responsible for analysis and design of information systems
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Systems Analyst as a Facilitator
Whitten 12/55
Knowledge and Skills of Systems Analyst
KnowledgeInformation technologyComputer programming experience and expertiseGeneral business knowledge
SkillsProblem-solving Interpersonal communication Interpersonal relations Flexibility and adaptabilityCharacter and ethicsSystems analysis and design
Whitten
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2. Types of Information Systems and Systems Development
Transaction Processing Systems (TPS)Automate handling of data about business activities (transactions)Process orientation
Management Information Systems (MIS)Converts raw data from transaction processing system into meaningful formData orientation
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Types of Information Systemsand Systems Development (Cont.)
Decision Support Systems (DSS)Designed to help decision makersProvides interactive environment for decision makingInvolves data warehouses, executive information systems (EIS)Database, model base, user dialogue
Expert Systems
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Types of Information Systems
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Summary of Information Systems Types
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3. Developing Information Systems
System Development Methodology is a standard process followed in an organization to conduct all the steps necessary to analyze, design, implement, and maintain information systems
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Systems Development Life Cycle (SDLC)
Traditional methodology used to develop, maintain, and replace information systemsPhases in SDLC:
PlanningAnalysisDesignImplementationMaintenance
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Standard and Evolutionary Views of SDLC
FIGURE 1-3 Evolutionary modelFIGURE 1-2The systems development life cycle
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Systems Development Life Cycle (Cont.)
Planning – an organization’s total information system needs are identified, analyzed, prioritized, and arranged
Analysis – system requirements are studied and structured logical system specification (model)
Design – a description of the recommended solution is converted into physical system specifications
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Systems Development Life Cycle (Cont.)
Logical design – all functional features of the system chosen for development in analysis are described independently of any computer platform
Physical design – the logical specifications of the system from logical design are transformed into the technology-specific details from which all programming and system construction can be accomplished
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Logical Design vs.Physical Design
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Systems Development Life Cycle (Cont.)
Implementation – the information system is coded, tested, installed and supported in the organization
Maintenance – an information system is systematically repaired and improved
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SDLC-based Guide to Hoffer’s Book
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4. Heart of the Systems Development Process
Current practice combines analysis, design, and implementation into a single iterative and parallel process of activities
FIGURE 1-8The heart of systems development
FIGURE 1-7The analysis–design–code–test loop
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Traditional Waterfall SDLC
One phase begins when another completes, little backtracking and looping
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Problems with 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
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4.1 Different Approaches to Improving Development
PrototypingComputer-Aided Software Engineering (CASE) ToolsJoint Application Design (JAD)Rapid Application Development (RAD)Agile MethodologieseXtreme Programming
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a) Prototyping *
Iterative development processRequirements quickly converted to a working systemSystem is continually revisedClose collaboration between users and analysts
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Prototyping (Cont.)
1 2
3 4
5
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b) Computer-Aided Software Engineering (CASE) ToolsDiagramming tools enable graphical representation
Computer displays and report generators help prototype how systems “look and feel”Analysis tools automatically check for consistency in diagrams, forms, and reports
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CASE Tools (Cont.)
Central repository for integrated storage of diagrams, reports, and project management specificationsDocumentation generators standardize technical and user documentationCode generators enable automatic generation of programs and database code directly from design documents, diagrams, forms, and reports
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CASE Tools (Cont.)
Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 36/55
c) Joint Application Design (JAD)
Structured process involving users, analysts, and managersSeveral-day intensive workgroup sessionsPurpose to specify or review system requirements
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d) Rapid Application Development (RAD)
Methodology to radically decrease design and implementation timeInvolves: extensive user involvement, prototyping, JAD sessions, integrated CASE tools, and code generators
FIGURE 1-11RAD life cycle
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Service-Oriented Architecture (SOA)
An approach to systems development based on building complete systems through assembling software components, each of which model generic business functions
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Service-Oriented Architecture (SOA)(Cont.)
FIGURE 1-12Illustration of a service, a credit check,used by applications and other services
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e) Agile Methodology
Motivated by recognition of software development as fluid, unpredictable, and dynamicThree key principles
Adaptive rather than predictiveEmphasize people rather than rolesSelf-adaptive processes
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The Agile Methodologies group argues that software development methodologiesadapted from engineering generally do not fit with real-world software development.
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When to use Agile Methodologies
If your project involves:Unpredictable or dynamic requirementsResponsible and motivated developersCustomers who understand the process and will get involved
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f) eXtreme Programming
Short, incremental development cyclesAutomated testsTwo-person programming teams
Coding and testing operate togetherAdvantages:
Communication between developersHigh level of productivityHigh-quality code
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5. Object-Oriented Analysis and Design (OOAD)
Based on objects rather than data or processes
Object: a structure encapsulating attributes and behaviors of a real-world entity
Object class: a logical grouping of objects sharing the same attributes and behaviors
Inheritance: hierarchical arrangement of classes enable subclasses to inherit properties of super-class
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Rational Unified Process (RUP)
An object-oriented systems development methodologyRUP establishes 4 phases of development: inception, elaboration, construction, and transitionEach phase is organized into a number of separate iterations
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FIGURE 1-13Phases of OOSAD-based development
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SummaryInformation systems analysis and design (SAD)Different types of information systemsInformation Systems Development Life Cycle (SDLC)Rapid Application Development (RAD), Prototyping, Joint Application Development (JAD), and Computer Aided Software Engineering (CASE)Agile methodologies and eXtreme programmingObject Oriented Analysis and Design and the Rational Unified Process (RUP)
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Questions and Answers
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Further Read
J.L.Whitten, L.D.Bentley, & K.C.Dittman, Systems Analysis and Design Method, 7th edition, McGraw-Hill, 2007K.E.Kendall and J.E.Kendall. Systems Analysis and Design, 6th edition, Prentice-Hall, 2005W.S.Davis Business Systems Analysis and Design, Wadsworth, 1994A. Dennis & et.al. System Analysis and Design, John Wiley, 2006 M.L. Gibson and C.T. Hughes. Systems Analysis and Design: A Comprehensive Methodology with CASE, Boyd & Fraser, 1994
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Teamwork Assignment
TopicForm a team of 10 students:
No, ID, name, email addresses (sort by ID)Mark ‘*’ for a leader & ‘**’ for an auditor after ID
Email to: [email protected]: all team members (to build a mailing list)
Subject: SA-N# (xxx) or SA-W# (xxx)where # is a team no. & ‘xxx’ is week-No(1..15)
Submit Date: (next week) one day before a class / Time: 1.00 p.m.
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Quiz 11.The __________________________ is the
traditional methodology used to develop, maintain, and replace information systems.
2.The first phase in the systems development life cycle (SDLC) is _______.
3. ______________________________ is a structured process in which users, managers, and analysts work together for several days in a series of intensive meetings to specify or review system requirements.
4. The output from the analysis phase is the _____________________.
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Exercise
1 List & explain some of the problems with the traditional waterfall SDLC.
2 Explain how prototype might be used as part of SDLC.
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Enemy
Inadequate & unstable requirementsInadequate customer communicationPoor team communicationUnnecessary complexityIneffective team behavior
(OO project management using UML)
