INTRODUCTION Overview of Systems Analysis Slide 1 Power

INTRODUCTION Overview of Systems Analysis Slide 1 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Key Ideas Many systems failures were because analysts tried to build wonderful systems without understanding the organization and applying a systematic approach. 2 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Key Ideas The systems analyst is a key person analyzing the business, identifying opportunities for improvement, and designing information systems to implement these ideas. It is important to understand develop through practice the skills needed to successfully design and implement new information systems. 3 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Types of Information Systems Transaction Processing Systems Management Information Systems Decision Support Systems Expert Systems Development of these systems require a good understanding of business processes and data 4 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Systems Development Lifecycle Approach The project Moves systematically through phases where each phase has a standard set of outputs Produces project deliverables Uses deliverables in implementation Uses gradual refinement and an iterative approach 5 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Project Phases Planning Why build the system? Analysis What will the system be? Design How will the system work? Implementation System delivery 6 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Planning Identifying business value Analyze feasibility Develop work plan Staff the project Control and direct project 7 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Analysis Information gathering Process modeling Data modeling 8 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Design Physical design Architectural design Interface design Database and file design Program design 9 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Implementation Construction Installation 10 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Processes and Deliverables Process Planning Project Plan Analysis System Proposal Design Implementation 11 Product System Specification New System and Maintenance Plan Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

What Is a Methodology? A formalized approach or series of steps Writing code without a wellthought-out system request may work for small programs, but rarely works for large ones. 12 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Structured Design Projects move methodically from one to the next step Generally, a step is finished before the next one begins 13 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Waterfall Development Method 14 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Pros and Cons of the Waterfall Method Pros Identifies systems requirements long before programming begins Cons Design must be specified on paper before programming begins Long time between system proposal and delivery of new system 15 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Alternatives to the SDLC Rapid Application Development (RAD) Prototyping 16 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Rapid Application Development Critical elements CASE tools JAD sessions Fourth generation/visualization programming languages Code generators 17 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

How Prototyping Works 18 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Object-Oriented Analysis and Design Attempts to balance emphasis on data and process Uses Unified Modeling Language (UML) for diagramming Use-case Driven Architecture Centric ± Functional, Static, and Dynamic views Iterative and Incremental 19 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Key Elements Classes -- template to define objects Instances -- specific examples of class members Objects -- building block of the system Attributes -- describe data aspects of the object Methods -- the processes the object can perform Messages -- instructions sent to or received from other objects 20 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

A Class and Its Objects Instantiated Objects of the Class PATIENT 1: TOP PACKAGE: PATIENT Class -Name = Teresa Marks -Birthdate = March 16, 1975 -Phone number = 314 -997 -3456 PATIENT -Name -Birthdate -Phone Number +Insert ()() +Delete ()() Attributes PATIENT 2: TOP PACKAGE: PATIENT Methods 21 -Name = Mel Bourne -Birthdate = May 11, 1965 -Phone number = 314 -997 -3219 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

The Key to Reusability Information hiding is the principle that only information required to use the object is available outside the object Encapsulation is the mechanism that combines data and processes in a single object 22 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

UML Unified Modeling Language The full UML provides 9 separate diagramming techniques 23 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Summary The Systems Development Lifecycle consists of four stages: Planning, Analysis, Design, and Implementation There are two major development methodologies: the waterfall method, RAD/Prototyping 24 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.

Summary There are six major elements in Object. Oriented design: classes, objects, instances, attributes, methods, and messages. Encapsulation, Inheritance, and Polymorphism are also important objectoriented concepts There are five major team roles: business analyst, systems analyst, infrastructure analyst, change management analyst and project manager. 25 Power. Point Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.