Chapter 1 Development Methodologies / SDLC

1. Modern Systems Analysisand DesignSeventh EditionJeffrey A. Hoffer Joey F. GeorgeJoseph S. Valacich Chapter 1 Development Methodologies / SDLC

2. Outline • Systems Development Life Cycle • Planning • Analysis • Design • Implementation • Maintenance • Methodologies

3. Process of System Development System Development Process • a set of activities, methods, best practices, deliverables, and automated tools that stakeholders use to develop and maintain information systems and software. • “Every medium to large corporation and every custom software producer will have its own specific life cycle or systems development methodology in place.” (Hoffer) • Shift in focus from custom-designed, stand-alone applications to implementing packaged software, such as ERP and data warehousing systems, and integrating outsourced software into the organization’s existing applications.

4. Life Cycle versus Methodology System Life Cycle • Divides the life of an information system into two stages, systems development and systems operation and support. System Development Methodology • A very formal and precise system development process that defines a set of activities, methods, best practices, deliverables, and automated tools that system developers and project managers are to use to develop and maintain information systems and software.

5. Conversion LIFE CYCLE STAGE LIFE CYCLE STAGE Lifetime System Operation System Development and Support of a System using using System Development Information Technology Methodology Obsolescence A System Life Cycle

6. Principles of System Development • Get the owners and users involved. • Use a problem-solving approach. • Establish phases and activities. • Establish standards for development and documentation. • Justify systems as capital investments. • Don’t be afraid to cancel or revise scope. • Divide and conquer. • Design systems for growth and change. • Proper planning and project management

7. Systems Development Life Cycle • Series of steps used to manage the phases of development for an information system • Consists of five phases: • Planning • Analysis • Design • Implementation • Maintenance

8. The SDLC • Planning • Project identification and selection • Project initiation and planning • Analysis • Determine system requirements (WHAT users want) • Modeling possible solutions (HOW to satisfy user needs) • Design • Logical design • Physical design • Implementation • Maintenance/Support Frontend A D Backend I

9. Systems Development Life Cycle • Phases are not necessarily sequential • Each phase has a specific outcome and deliverable • Individual companies use customized life cycles Cross life cycle activities • Activities that overlap many or all phases of the methodology. • Fact-finding • Documentation and presentation • Feasibility analysis • Process and project management

10. Phases of the Systems Development Life Cycle • Planning (a) Project Identification and Selection • Two Main Activities • Identification of need • Prioritization and translation of need into a development schedule • Helps organization to determine whether or not resources should be dedicated to a project. (b) Project Initiation and Planning • Two Activities • Formal preliminary investigation of the problem at hand • Presentation of reasons why system should or should not be developed by the organization

11. Phases of the Systems Development Life Cycle (Cont.) • Analysis • Determine System Requirements • Study of current procedures and information systems • Determine requirements • Study current system • Structure requirements and eliminate redundancies (b) Modeling Possible Solutions • Generate alternative designs • Compare alternatives • Recommend best alternative

12. Phases of the Systems Development Life Cycle (Cont.) • Design (a) Logical Design • Concentrates on business aspects of the system (b) Physical Design • Technical specifications • Implementation • Hardware and software installation • Programming • User Training • Documentation • Maintenance • System changed to reflect changing conditions • System obsolescence

13. Structured Development Information Engineering Prototyping Joint Application Design Commercial Methodologies (i.e., STRADIS, Navigator) Agile Service-Oriented Architecture Object-Oriented Development Spiral Model Transform Model Jackson Structured Development Code & Fix Model Participatory Design eXtreme Programming Common Development Methodologies and Techniques

14. Model-Driven Development Route Modeling • The act of drawing one or more graphical representations (or pictures) of a system. • Modeling is a communication technique based upon the old saying, “a picture is worth a thousand words.” Model-drivendevelopment • Techniques that emphasize the drawing of models to help visualize and analyze problems, define business requirements, and design information systems. • Structured systems analysis and design —process-centered • Information engineering (IE) —data-centered • Object-oriented analysis and design (OOAD) —object-centered (integration of data and process concerns)

15. Structured Development • Based on the principles of: • Modularization • Top-down decomposition • Process-driven • Structured programming, design and analysis

16. Information Engineering • Data-oriented technique • Emphasis on planning • Applied to the organization as a whole rather than an ad hoc, project-by-project basis

17. Prototyping • Principle: a user can tell you better what they DON’T want than what they DO want • Expendable (throw-away) prototyping: • Discarded after use • Used to support the analysis and design phases • Evolutionary prototyping: • Prototype evolves into the final system • Is it a methodology? • Rapid application development (RAD) • Techniques emphasizing extensive user involvement in the rapid and evolutionary construction of working prototypes of a system to accelerate the system development process.

18. Joint Application Design (JAD) • Users, Managers and Analysts work together for several days • System requirements are reviewed • Structured meetings

19. Commercial Off-the-Shelf Software Route • Software package or solution that is purchased to support one or more business functions and information systems.

20. Improving IS Development Productivity • Computer-aided software engineering (CASE) tools • Facilitate creation of a central repository for system descriptions and specifications

21. CASE Architecture

22. Agile Methodologies • Principles: • Focus on adaptive methodologies (not predictive) • Focus on people (not roles) • Focus on self-adaptive processes (refine and improve development process) • Argues that engineering and software development are not the same. • Engineering requirements are well understood. • Software requirements are not well understood and change continually.

23. Service-Oriented Architecture • Build systems around generic services or specific business functions. • Reuse in many different applications. • Example: credit check application • Any time the business would need a credit check (when adding a new customer, entering a new order, and so forth), the current credit check “service” application would be altered to fit that business function.