OPS5 in Architecture: Four Test Cases

The advantage of production systems such as OPS5 over structured programming becomes most evident when they are applied to large, ill-structured problems. These applications are abundant in architectural design. Although efficient algorithms exist for some domains in architecture, empirical knowlede is essential in others. This situation calls for hybrid implementations with traditional efficient procedural packages providing support for production system front ends. OPS5 is a general-purpose production system language. In each one of the four test cases, one particular aspect of OPS5 was explored in-depth.

The first test case is an attempt to capture the rules of thumb, algorithms and decision tables contained in the ""Small Office Design Handbook"" and to turn it into an interactive computerized design consultant. The second test case is an attempt to build an intelligent knowledge acquisition tool to extract design knowledge from designers with no or very little programming knowledge, and to transform that knowledge directly into OPS5.The expert system has a problem decomposition module and an expert system building component.

The third test program is it knowledge based ROOF DESIGNER. It addresses a subset of the factors and heuristics that designers use to decide on the shape of roofs. These factors and heuristics were determined with a protocol analysis and then transformed into OPS5 rules. The last test case uses TOPSI, the IBM AT implementation of OPS5, and DRAW, a GKS based graphics program with three dimensional extensions. DRAW acts as a high quality graphics output device of programs written in TOPSI. A user interface allows the construction of new TOPSI rules from graphic input in DRAW.

L'utilisation de systemes de production tels que OPS5 apparait nettement preferable a celle de la programmation structuree dans le cas de problemes complexes et mal structures. De tels problemes sont frequents en design architectural. Bien que des algorithmes efficaces existent pour certains domaines en architecture, des connaissances empiriques sont essentielles dans d'autres cas. Cette situation necessite le developpement de systemes hybrides comprenant des parties procedurales associees a des modules utilisant un langage de systeme de production tel que OPS5. Nous allons decrire, pour chacune des quatre applications presentees, un aspect particulier d'OPS5.

Le premier programme tente de reproduire les algorithmes, regles et tables de decision decrits clans le livre 'Small Office Design Handbook', afin d'en faire un outil de design interactif.

Dans le deuxieme cas, nous avons tente de developper un outil permettant d'extraire lesconnaissances en design de concepteurs sans formation informatique particuliere, et de transcrire ces connaissances dans OPS5. Le systeme comprend deux parties: un module de decomposition de probleme, et un generateur de systeme expert. Le troisieme programme d'essai est un generateur de toitures, qui utilise des parametres et des techniques employes par les concepteurs pour definir la forme des toitures. Ces facteurs et raisonnements ont ete determines par des analyses de demarche, et transcrits en regles de production OPS5. Le dernier programme a ete developpe en TOPSI, la version d'OPS5 pour IBM AT, et utilise DRAW, on programme graphique 3D, comme moyen de visualisation graphique. Un Interface permet egalement de creer graphiquement des regles de production OPS5.