This chapter include objectives: To introduce software process models; to describe three generic process models and when they may be used; to describe outline process models for requirements engineering, software development, testing and evolution; to explain the Rational Unified Process model; to introduce CASE technology to support software process activities. | Software Processes Objectives To introduce software process models To describe three generic process models and when they may be used To describe outline process models for requirements engineering, software development, testing and evolution To explain the Rational Unified Process model To introduce CASE technology to support software process activities Topics covered Software process models Process iteration Process activities The Rational Unified Process Computer-aided software engineering The software process A structured set of activities required to develop a software system Specification; Design; Validation; Evolution. A software process model is an abstract representation of a process. It presents a description of a process from some particular perspective. Generic software process models The waterfall model Separate and distinct phases of specification and development. Evolutionary development Specification, development and validation are interleaved. Component-based . | Software Processes Objectives To introduce software process models To describe three generic process models and when they may be used To describe outline process models for requirements engineering, software development, testing and evolution To explain the Rational Unified Process model To introduce CASE technology to support software process activities Topics covered Software process models Process iteration Process activities The Rational Unified Process Computer-aided software engineering The software process A structured set of activities required to develop a software system Specification; Design; Validation; Evolution. A software process model is an abstract representation of a process. It presents a description of a process from some particular perspective. Generic software process models The waterfall model Separate and distinct phases of specification and development. Evolutionary development Specification, development and validation are interleaved. Component-based software engineering The system is assembled from existing components. There are many variants of these models . formal development where a waterfall-like process is used but the specification is a formal specification that is refined through several stages to an implementable design. Waterfall model Waterfall model phases Requirements analysis and definition System and software design Implementation and unit testing Integration and system testing Operation and maintenance The main drawback of the waterfall model is the difficulty of accommodating change after the process is underway. One phase has to be complete before moving onto the next phase. Waterfall model problems Inflexible partitioning of the project into distinct stages makes it difficult to respond to changing customer requirements. Therefore, this model is only appropriate when the requirements are well-understood and changes will be fairly limited during the design process. Few business systems have stable requirements. The .