vel Design) phases of the system and module interfaces. development lifecycle. (See Figure 25.4). Accepting this, KADS 1 to 3 = Analysis - Specifying what the system will do. covers the development activities required to build seven key 4 = System Design - Specifying the overall system architec- models over these phases. The KADS modelling process involves ture. translating the real world problem into an abstract form and map- ping the abstraction onto a system design. The seven models pro- 5 to 7 = KBS Design - Specifying how the KBS subsystem is to work. duced are: 1. Process Model. An abstract representation of the overall or- 25.4.5 A Lifecycle based on Rapid ganisational process that the system will be involved in. It Prototyping Techniques describes the tasks to be performed within that process, down to the level where it can be decided whether they will be The lifecycle given in Figure 25.5 has been shown to provide a performed by the system or not. powerful way of understanding and documenting the real needs of Co-operation Model. An abstract representation of the way the the user by building a prototype which is then subject to extensive future system will interact with its environment. In particular, user evaluation; successive iterations ensure that the final version Concept System in Use Feasibility Maintenance Study Product Evaluation & Definition Acceptance High-level Integration & Design System Test Detailed Module Design Validation Implementation High level of support Lesser level of support Figure 25.4 KADS in the product development lifecycle Software simulation 25/11 EXAMPLE DELIVERABLES SYSTEM DEVELOPMENT PHASES 1 Determine Project Scope 2 Analyse Present System 3 Identify User Population Project Definition 4 Specify System Objectives 1 Interview Intended Users (Requirements Analysis) 2 Observe Intended Users (Task Analysis) Requirements 3 Identify User Characteristics Capture & Analysis 4 Specify Usability Objectives 1 System Alternatives 2 Cost/Benefit Analysis Business 3 Requirements Specif