Handbook of Reliability, Availability, Maintainability and Safety in Engineering Design - Part 6 studies the combination of various methods of designing for reliability, availability, maintainability and safety, as well as the latest techniques in probability and possibility modelling, mathematical algorithmic modelling, evolutionary algorithmic modelling, symbolic logic modelling, artificial intelligence modelling, and object-oriented computer modelling, in a logically structured approach to determining the integrity of engineering design. . | 30 1 Design Integrity Methodology The blackboard model consists of a data structure the blackboard containing information that permits a set of modules or knowledge sources to interact. The blackboard can be seen as a global database or working memory in which distinct representations of knowledge and intermediate results are integrated uniformly. The blackboard model can also be seen as a means of communication among knowledge sources mediating all of their interactions. Finally it can be seen as a common display review and performance evaluation area. It may be structured so as to represent different levels of abstraction and also distinct and or overlapping phases in the design process. The division of the blackboard into levels parallels the process of hierarchical structuring and of abstraction of knowledge allowing elements at each level to be described approximately as abstractions of elements at the next lower level. The partition of knowledge into hierarchical levels is useful in that a partial solution . group of hypotheses at one hierarchical level can be used to constrain the search at lower levels typical of systems hierarchical structuring in engineering design. The blackboard thus provides a shared representation of a design and is composed of a hierarchy of three panels A geometry panel which is the lowest-level representation of the design in the form of geometric models. A feature panel which is a symbolic-level representation of the design. It provides symbolic representations of features constraints specifications and the design record. The control panel which contains the information necessary to manage the operation of the blackboard model. f Implementation and Analysis When dealing with the automated generation of solutions to design problems in a target engineering design project it is necessary to distinguish between design and performance. The former denotes the geometric and physical properties of a solution that design engineers .
