TRAPS - A TIME-DEPENDENT RESOURCE-ALLOCATION LANGUAGE

A general language for specifying resource allocation in Scheduling pr oblems is presented. TRAPS is a generalization of the RAPS (Resource A llocation Problem Specification) language developed by the authors (So lotorevsky, Gudes & Meisels, 1994). TRAPS enables the specification of a scheduling problem by adding built in time operators, on top of exi sting terms for resources, activities, allocation rules and constraint s. In this way TRAPS provides a convenient knowledge acquisition tool. The language syntax is powerful and allows the specification of rules and constraints which are difficult to formulate with traditional app roaches, and it also supports the specification of various control and backtracking strategies. The generalized inference engine that runs c ompiled TRAPS programs is enhanced to provide all needed operations fo r a typical PERT/CPM calculations on a schedule. This engine acts as a n expert system shell and is called ESRA (Expert System for Resource A llocation). The performance of TRAPS combined with ESRA is demonstrate d by analyzing its solution of a typical scheduling problem, that of a software management project. The analysis shows that certain heuristi cs which formed the basis of our strategy for resource allocation (Sol otorevsky, Gudes & Meisels, 1994) perform very well also in the (time dependent) scheduling domain.