Systems Analysis and Design Alan Dennis and Barbara Haley Wixom John Wiley & Sons, Inc. Slides by Fred Niederman PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Introduction Chapter 1 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Key Ideas The systems analyst is a key person analysing the business, identifying opportunities for improvement, and designing information systems to implement these ideas. It is important to understand and develop through practice the skills needed to design and implement new information systems successfully. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

THE SYSTEMS DEVELOPMENT LIFE CYCLE PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Project Phases Planning Analysis Design Implementation Why build the system? Analysis What, when, where will the system be? Design How will the system work? Implementation System delivery PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

A “Simple” Process for Making Lunch PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Planning Identifying business value Analyse feasibility Develop work plan Staff the project Control and direct project PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Analysis Analysis Information gathering Process modeling Data modeling PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Design Physical design Architectural design Interface design Database and file design Program design PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Implementation Construction Installation PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Processes and Deliverables Product Planning Analysis Design Implementation Project plan (requirements) System proposal (function spec) System spec (detailed design) New system & Maintenance plan PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

SYSTEM DEVELOPMENT METHODOLOGIES PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

What Is a Methodology? A formalised approach or series of steps Examples Process-centred Data-centred Object-oriented PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Waterfall Development Method PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Pros and Cons of the Waterfall Method Identifies systems requirements long before programming begins Design must be specified on paper before programming begins Long time between system proposal and delivery of new system PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Alternatives to the SDLC Parallel Development Rapid Application Development (RAD) Phased Development Prototyping Spiral Development Packaged Systems PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Parallel Development Method PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Pros and Cons of Parallel Development Reduces Scheduled Time Still Uses Paper Documents Less Chance of Rework Sub-projects May Be Difficult to Integrate PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Rapid Application Development CASE tools Joint application design (JAD) sessions Fourth generation/visualisation programming languages Code generators PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Three RAD Categories Phased development Prototyping A series of versions Prototyping System prototyping Throw-away prototyping Design prototyping PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

How Prototyping Works PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Throwaway Prototyping PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Criteria for Selecting the Appropriate Methodology Clear user requirements Familiar technology Complexity Reliability Time schedule Schedule visibility PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.

Summary The Systems Development Lifecycle: Development methodologies: Planning, Analysis, Design, and Implementation Development methodologies: the waterfall method, the parallel development method, the phased development method, system prototyping and design prototyping. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved.