Development Models Introduction

Will be discussing models used in Systems Engineering field with emphasis on software development process and role of models in Information Systems design.
Specifically look at role models play in development of software-based systems.
These models used across other engineering disciplines, original mnemonic SDLC stood for Standard Development Life Cycle.
Software produced to support systems – different descriptions include; data processing systems, computer systems, information systems and knowledge based systems.
Before 1950’s, software developed uniquely/application, no formal approach.
Programme code listing may have been documented but not other documentation  available.
Programme is a low abstraction level model – very detailed.
Developed systems became more complex & expensive – different models developed to support software and systems development.