1-1 © prentice hall, 2007 chapter 1: the object-oriented systems development environment...
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1-1© Prentice Hall, 2007
Chapter 1:Chapter 1:The Object-Oriented Systems The Object-Oriented Systems
Development EnvironmentDevelopment Environment
Object-Oriented Systems Analysis and Design
Joey F. George, Dinesh Batra,
Joseph S. Valacich, Jeffrey A. Hoffer
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Chapter ObjectivesChapter Objectives
After studying this chapter you should be able to:– Define information systems analysis and design.
– Explain the basics about systems.
– Describe the information systems development cycle (SDC).
– Describe TPS, MIS, DSS, and ES/EIS.
– Describe the role of systems analyst.
– Recount the evolution of system development methodologies.
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What Is Systems Analysis and What Is Systems Analysis and Design?Design?
The process of developing and maintaining an information system
Main goal – improve organizational systems via software to help accomplish business tasks efficiently and easily
Requires knowledge of:– Organization’s objectives, structure, processes
– How to exploit information technology for advantage
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Core ConceptsCore ConceptsMajor goal of systems analysis – improve
organizational systemsDevelopment/acquisition of application
softwareOther elements of IS – hardware, system
software, documentation, training materials, job roles, controls and security, people
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What Is a System?What Is a System?
A group of interrelated procedures used for a business function, with an identifiable boundary, working together for some purpose.
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Characteristics of SystemsCharacteristics of SystemsComponents – irreducable or aggregate parts of a
system (also called subsystems)Interrelationships – associations and dependencies
between components of a systemBoundary – divides system from environmentPurpose – goal or function of a systemInterfaces – points of contact between system and
environmentInputs – data from environment to systemOutput – data from system to environmentConstraints – limit to what the system can accomplish
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Important System ConceptsImportant System Concepts
Decomposition – breaking down a system into smaller constituents
Modularity – the result of decomposition; parts of a system
Coupling – extent of dependencies between subsystems
Cohesion – extent to which a subsystem performs a single function
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Transaction Processing System Transaction Processing System (TPS)(TPS)
Automate the handling of data for business activities or transactions
Goal: improve transaction processing by increasing speed, enhancing productivity, improving efficiency and accuracy
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Management Information System Management Information System (MIS)(MIS)
Use raw data from TPS systems, and converts them into meaningful aggregate form, resulting in summary reports
Goal: provide the information that helps managers in their jobs
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Decision Support System (DSS)Decision Support System (DSS)Combine databases, mathematical or graphical
models, and interactive user interfaces or dialogues allowing users to manipulate data and models
Include what-if analyses, executive information systems, data warehouses, knowledge management systems
Goal: support decision-making with unstructured and unpredictable problems
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IS Department Organization ChartIS Department Organization Chart
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IS ComponentsIS Components
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Chief information officerChief Technology officerOperation groupDevelopment groupOutsourcing relation groupData administration staff
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Characteristics of Sucessful Characteristics of Sucessful TeamsTeams
Diversity of backgrounds, skills, and goalsTolerance of diversity, uncertainty, and ambiguityClear and complete communicationsTrustMutual respect and putting personal interests
second to the teamReward structure that promotes shared
responsibility and accountability
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The Role of the Systems AnalystThe Role of the Systems Analyst
Skills required: analytical, technical, managerial, interpersonal
Fluency in “systems thinking”
Liaison between users, programmers, and other systems professionals
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Evolution of System Evolution of System Development MethodologiesDevelopment Methodologies
SDLC– Systems Development Life Cycle
Structured Analysis and Design– Use of Data Flow Diagrams
Data-Oriented Methodology– Use of Entity Relation Diagrams
Object-Oriented Methodology– Use of Unified Modeling Language (UML) Diagrams
Agile Methodologies– Adaptive, people-oriented approach
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Systems Planning and SelectionSystems Planning and Selection
Analyze and arrange organization’s information needs, identify and describe potential project, determine system scope, and provide a business case for continuing with the project
Feasibility analysis: determine economic and organizational impact of the system
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Systems AnalysisSystems Analysis
Thorough study of organization’s current system and processes, determination of system requirements, structuring requirements, generate alternative design strategies.
Use of UML for system modelingGoal: describe what needs to be done
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Systems DesignSystems Design
Translating alternative solution generated by analysis phase into detailed logical and physical system specifications.– Logical design: not tied to any hardware or
software platform– Physical design: specific programming
languages, databases, architecturesGoal: identify how the task will be
accomplished
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System Implementation and System Implementation and OperationOperation
Information system is coded, tested, and installed, and undergoes periodic corrections and enhancements
Goal: provide a fully operational system
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Key Differences Between Structured and Key Differences Between Structured and Object-Oriented Analysis and DesignObject-Oriented Analysis and Design
Structured Object-Oriented
Methodology SDLC Iterative/Incremental
Focus Processs Objects
Risk High Low
Reuse Low High
Maturity Mature and widespread Emerging
Suitable for Well-defined projects with stable user requirements
Risky large projects with changing user requirements
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Construction is the hardest part
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InceptionInception
Defining the scope, determining the feasibility, understanding user requirements, preparing a software development plan
Relatively short, low resource requirements
Focus on planning and analysis
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ElaborationElaboration
Detailed user requirements and baseline architecture is established
Fairly long, but not high in resource demand
Focus on analysis and design
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ConstructionConstruction
Coding, testing, and documenting code
Longest and most resource-intensive
Focus is on implementation tasks
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TransitionTransition
System is deployed and users are trained and supported
Short-term, but resource-intensive
Focus is on installation, training, and support
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