A brief overview of 3 Methodologies for comparison

Structured Systems Analysis and Design Method (SSADM)

• Developed by the UK government in 1982; mandatory use for some Civil Service applications; now mature and widely used • Use supported by many CASE tools (including Select) • Builds on the traditional Systems Development Life Cycle and has clearly defined stages; it thus lends itself to project management techniques • Provides development staff with detailed guidelines, requiring, for example, the completion of pre-printed documents • Data driven ; based on assumption that systems have an underlying data structure that changes little over time – however, later versions of SSADM have placed increasing emphasis on user • Thorough quality assurance: deliverables at every stage reviewed in structured walkthroughs and signed off by users • Separates the logical view of the system from the physical • Provides 3 main views of the system, the Data Flow Diagram, the Entity Relationship Diagram and the Entity Life History, which can be cross-checked one against the other.

Rapid Applications Development (RAD)

• The name speaks for itself – need for RAD driven by rapidly changing business needs • Can be viewed as an example of the spiral model for systems development. The spiral model acknowledges the stages that form the SDLC but builds into each stage iteration, prototyping and extensive user involvement. • Prototyping may be of whole system or part of the system to tease out particular problem areas • Early versions of prototype may be paper-based • Important users are identified and involved in workshops at early stages of development; these are terms Joint Requirements Planning and Joint Application Design workshops • JAD designed to gather all the project stakeholders together in one forum in order to reach mutually