1. Chapter 1: The Object-Oriented Systems Development Environment Object-Oriented Systems Analysis and Design Joey F. George, Dinesh Batra, Joseph S. Valacich, Jeffrey A. Hoffer

2. Chapter 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, and DSS. –Describe the role of systems analyst. –Recount the evolution of system development methodologies.

3. What Is Systems Analysis and Design? Systems analysis and design is the process of analyzing user requirements, designing a solution to meet those needs, and ultimately building a software system that meets those needs and requirements. Requires knowledge of: –The business objectives, structure, processes –Information technology opportunities and constraints

5. What Is a System? A group of interrelated processes and procedures used for a business function, with an identifiable boundary, working together for some purpose. A system has clear identifiable functional boundaries. Example a payroll system should not accept payments from outside customers. An email system should not create a spreadsheet

6. Characteristics of Systems Input – data from environment to system Output – data from system to environment Components – objects or a subparts of systems operating independently Interrelationships – associations between components of a system Interfaces – mechanism for interacting with components Boundary – identify the functionality limit of system

8. Important System Concepts Decomposition – breaking down a system into smaller constituents Modularity – the result of decomposition; parts of a system Coupling – dependencies between subsystems Cohesion – extent to which a subsystem performs a single function

9. Type Of Systems TPS – Transaction Processing System. Increases efficiency and productivity a.k.a. OLTP (online transactional processing) MIS – Management Information System. Converts data into information to help management optimize business decisions DSS – Decision Support System Interactively assist with decision making. Allows for what-if scenarios & comparisons

11. Transaction Processing System (TPS) Automate the handling of data for business activities or transactions Also known as OLTP Online Transactional Processing system Goal: improve transaction processing by increasing speed, enhancing productivity, simplifying processes

12. Management Information System (MIS) Use raw data from TPS systems, and converts them into meaningful aggregate form. Converts Data to Information Goal: provide information to management to help them manage the business

13. Decision Support System (DSS) Interactively assist with decision making by applying mathematical or logical models and a dialogue of interactions to solve unstructured problems (allow for what ifs) Goal: provide comparisons of alternatives and recommendation of preferred option

14. The Four Steps of Systems Development Life Cycle Systems Planning, Selection & Management Systems Analysis Systems Design Systems Implementation, and Operations & Maintenance (Sometimes Operations & Maintenance is viewed as a separate 5 th step.)

16. Systems Planning, Selection & Management 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 Management across all phases of development

17. Systems 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 modeling Goal: describe what needs to be done

18. Systems 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. From the business view. –Physical design: specific programming languages, databases, architectures Goal: identify how the task will be accomplished

19. System Implementation and Operation Information system is coded, tested, and installed, and undergoes periodic corrections and enhancements Goal: provide a fully operational system, and the continued success of the system

20. The Role of the Systems Analyst Skills required: analytical, technical, managerial, interpersonal Liaison between users, programmers, and other systems professionals

21. Evolution of System Development Methodologies The output-Input based methodology - Examine the output will lead you to the requirements Structured Analysis and Design - Use of Data Flow Diagrams to represent data movement The System Development Life Cycle - System Planning, Analysis, Design & Implementation Object Oriented Systems Analysis & Design - Iterative & incremental approach to systems development - Use of Unified Modeling Language (UML) Diagrams

23. The current trend is to use OOSAD, but many organizations are still using structured analysis and design

24. Object Oriented Systems Analysis & Design The best OO systems analysis & design methodology is RUP (Rational Unified Process). The methodology calls for a 4 phase approach: Inception Elaboration Construction Transition - Each phase is applied iteratively & incrementally - Each phase applies the same 4 SDLC steps

25. Inception Phase Defining the scope, determining the feasibility, understanding user requirements, preparing a software development plan Relatively short, low resource requirements Focus on planning and initial analysis

26. Elaboration Phase Detailed user requirements and baseline architecture is established Fairly long, but not high in resource demand Focus on detail analysis and design

27. Construction Phase Coding, testing, and documenting code Longest and most resource-intensive Focus is on design and implementation

28. Transition Phase System is deployed and users are trained and supported Short-term, but resource-intensive Focus is on installation, training, and support

29. Construction is the longest part

30. Iterative & Incremental A key feature of RUP is the iterative and incremental nature of the development process. Iterative – means developing in pieces, and growing and improving each piece through successive iterations. Incremental – means developing in pieces, and progressively adding new pieces through successive iterations.

31. RUP Phases across SDLC steps Inception - mostly planning and analysis, low on design and implementation & operation. Elaboration - high on planning, additional analysis, mostly design, low on implementation & operation. Construction - high on planning, low on analysis, more design, mostly implementation & operations. Transition – high on planning, low on analysis and design, high on implementation & operations.

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33. Recap After studying this chapter we learned to: –Define information systems analysis and design. –Explain the basics about systems. –Describe the information systems development cycle (SDC). –Describe TPS, MIS, and DSS. –Describe the role of systems analyst. –Recount the evolution of system development methodologies.