ISTM 280, GWU1 Introduction to Systems Analysis and Design Lecture 1 Courtesy Subhasish Dasgupta

ISTM 280, GWU 2 Key Ideas Many failed systems were abandoned because analysts tried to build wonderful systems without understanding the organization. The primarily goal is to create value for the organization.

ISTM 280, GWU 3 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 and develop through practice the skills needed to successfully design and implement new information systems.

ISTM 280, GWU 4 The Systems Development Life Cycle: Major Attributes of the Lifecycle The project  Moves systematically through phases where each phase has a standard set of outputs  Produces project deliverables  Uses deliverables in implementation  Results in actual information system  Uses gradual refinement

ISTM 280, GWU 5 Project Phases Planning  Why build the system? Analysis  Who, what, when, where will the system be? Design  How will the system work? Implementation  System delivery

ISTM 280, GWU 6 Identifying business value Analyze feasibility Develop work plan Staff the project Control and direct project Planning

ISTM 280, GWU 7 Analysis Information gathering Process modeling Data modeling Analysis

ISTM 280, GWU 8 Physical design Architectural design Interface design Database and file design Program design Design

ISTM 280, GWU 9 Construction Installation Implementation

ISTM 280, GWU 10 Processes and Deliverables ProcessProduct Planning Analysis Design Implementation Project Plan System Proposal System Specification New System and Maintenance Plan

ISTM 280, GWU 11 Systems Development Methodology: What Is a Methodology? A formalized approach or series of steps Writing code without a well-thought-out system request may work for small programs, but rarely works for large ones.

ISTM 280, GWU 12 Structured Design Projects move methodically from one to the next step Generally, a step is finished before the next one begins

ISTM 280, GWU 13 Waterfall Development Method

ISTM 280, GWU 14 Pros and Cons of the Waterfall Method ProsCons 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

ISTM 280, GWU 15 Parallel Development

ISTM 280, GWU 16 Alternatives to the SDLC Rapid Application Development (RAD) Phased Development Prototyping Throw-Away Prototyping

ISTM 280, GWU 17 Rapid Application Development Critical elements  CASE tools  JAD sessions  Fourth generation/visualization programming languages  Code generators

ISTM 280, GWU 18 Rapid Application Development Categories Phased development  A series of versions Prototyping  System prototyping Throw-away prototyping  Design prototyping Agile Development Extreme Development

ISTM 280, GWU 19 How Prototyping Works

ISTM 280, GWU 20 Throwaway Prototyping

ISTM 280, GWU 21 Selecting the Appropriate Methodology Clarity of User Requirements Familiarity with Technology System Complexity System Reliability Short Time Schedules Schedule Visibility

ISTM 280, GWU 22 Information Systems Roles Business analyst System analyst Infrastructure analyst Change management analyst Project manager

ISTM 280, GWU 23 Object-oriented approach – Classes and Objects Class – Template to define specific instances or objects Object – Instantiation of a class Attributes – Describes the object Behaviors – specify what object can do

ISTM 280, GWU 24 Basic Characteristics of Object Oriented Systems Classes and Objects Methods and Messages Encapsulation and Information Hiding Inheritance Polymorphism and Dynamic Binding

ISTM 280, GWU 25 Object Oriented Systems Analysis and Design Use-case driven Architecture Centric Iterative and Incremental The Unified Process