Approaches to Systems Development

Week 2CMIS570

Tonight SDLC Other approaches CASE tools

Why study SA&D? “meat” of the IS function Winchester house example Art vs. Science

Methodologies Comprehensive, multiple-step approaches to systems

development Models

Representation of system, organization, etc. Techniques

Particular processes used when following methodology Tools

Computer programs which aid development process

Methodologies Rationale Defined stages allow for project

control Problems are easier and cheaper

to fix earlier in the process

SDLC Systems Development Life Cycle Traditional methodology used to

develop, maintain, and replace information systems. Orderly set of activities conducted

and planned for each development project.

Steps in SDLC Planning Analysis Design Implementation Support

SDLC

Project Planning

Analysis

Design

Implementation

Support

Requirements of SDLC Can define project boundary You know what you want the

system to do and can specify it in detail

Movement away from SDLC – WHY?

Variations we’ll be examining Traditional – SDLC Variations of the SDLC

RAD Spiral Approach Prototyping Extreme programming

Object Oriented Traditional UP

Package Software / ERP

Data versus Process Process-oriented approach

Focuses on how and when data are moved and changed

Data-oriented approach Focuses on the ideal organization of data rather

than on where and how data are used.

Computer-Aided Software Engineering (CASE) Software tools that provide automated

support for some portion of the systems development process.

Assists system builders in managing the complexities of information system projects and helps assure that high-quality systems are constructed on time and within budget.

Evolution of CASE

Art vs. Science Lack of consistency in systems

development Predominantly used with PCs Supports wide variety of system

development activities

CASE tools Diagramming tools Analysis tools

Tools that enable automatic checking for incomplete, inconsistent, or incorrect specifications in diagrams, forms, and reports

Central repository / Data dictionary Repository of all data definitions for all

organizational applications Documentation generators Code generators

Tools we have available VISIO Oracle

Next Week Homework #1 DUE:

Problem statement for your application

Read Chapter 3 Read Appendix A