 tailorable up it should reduce development time significantly. to a specific client's requirements, both in terms of the problem solving functionality and the clients' domain. 25.3.4 Knowledge based system techniques 2. General Purpose Systems. Systems that operate in a domain common to many potential customers' requirements. There is a group of techniques concerned with logic programming Bespoke Systems. Systems for specific users that are developed and reasoning via rules and constraints. In the limit the techniques for specific clients requiring specific problem solving in spe- aim to produce software to simulate human reasoning i.e. artificial cific domains. intelligence. The techniques most commonly used within the Tele- Embedded Systems. The KADS methods can be combined communications industry are Knowledge Based Systems (KBS) with other software development methodologies to produce and provide the user with a means of solving problems using rule 'embedded' systems, i.e. those in which an expert problem and constraint based data. Often the user can modify the rules, solving component is nested within a larger application. allowing the reasoning to be altered without any reprogramming. Adaptable Systems. The KADS methods provide an analysis Some of the domains in which KBS techniques are most applic- and design framework that allows a high degree of adaptability able are: to be built into a KBS SO that the same system can be used by different people for different purposes. 1. Automated equipment configuration. 2. Diagnostic software. 3. Network management, in particular identification of faults Lifecycle for each software design from a set of symptoms and dynamic reconfiguration. technique 4. Simulating network behaviour. 5. Controlling and monitoring manufacturing processes. 25.4.1 Formal methods lifecycle KBS has, in the past, been seen as having limited applicability and The stages in the formal methods lifecycle are the same as those in there are few methods and supporting tools available. However, the 