Dynamic Constraint Models for Complex Production Environments

Planning and scheduling attracts an unceasing attention of computer science community. However, despite of similar character of both tasks, in most current systems planning and scheduling problems are usually solved independently using different methods. Recent development of Constraint Programming brings a new breeze to these areas. It allows using the same techniques for modelling planning and scheduling problems as well as exploiting successful methods developed in Artificial Intelligence and Operations Research. Currently, scheduling is the most successful application area of constraint programming. In the paper we analyse the problems behind planning and scheduling in complex production environments. We give a survey of three conceptual models developed to model such environments. We discuss their industrial background and compare their advantages and disadvantages. The models were studied within the VisOpt project whose goal is to developed a generic scheduling engine applicable to various complex production environments. However the proposed conceptual models can be applied to other (non-production) problem areas where joined scheduling and planning capabilities are required.