Modeling constraint programs with software technology standards

Abstract

In [1] Puget argued for a "model-and-run" paradigm for constraint programming. He proposed to develop a standard file format to express CP models. There is no such unified modeling standard available to the CP community, so constraint programs cannot be developed independently from the used CP library and they are hard to maintain. This research targets platform-independent object-oriented modeling of constraint programs. It will be shown how CP models can be expressed using software technology standards, and further how these standards will enable automated transformation and execution of such models. The work reconsiders results published in [2]. There, we have formally shown how the Unified Modeling Language (UML) and the Object Constraint Language (OCL) can be used to create well formed models of constraint problems called Constraint Network Schemata (CNS). Resting upon this, the author now proposes to see Model Driven Architecture (MDA) as a chance for further research advances. Although this paper mainly presents ideas for the adaption of MDA techniques, some practical results where achieved already in the domain of surgery planning for hospitals. A first prototypic implementation exists which can solve XML-representations of CNS-models with our finite domain constraint solver firstcs. Therefore, the CNS-model and the input data of a constraint problem are processed from separate XML files to create a Constraint Satisfactory Problem (CSP) in a data-driven way. The CSP is then solved by firstcs and the solution is returned as an XML-file, too. Such processing simplifies the integration into complex business workflows and helps to increase the acceptance of CP in business applications. © Springer-Verlag Berlin Heidelberg 2005.