Constraint-Based Scheduling in Oz

It is discussed, how scheduling problems can be solved in the concurrent constraint programming language Oz. Oz is the first high-level constraint language, which offers an interface to invent new constraints in an efficient way using C++. Its multi-paradigm features including programmable search are unique in the field of constraint programming. Through the interface, algorithms from Operations Research and related fields can be incorporated. The algorithms can be combined through encapsulation into constraints and can communicate via shared variables. This is exemplified by the integration of new techniques based on edge-finding for job-shop and multi-capacitated scheduling. The viability of Oz as a platform for problem solving is also exemplified by a graphical scheduling workbench. The performance for job-shop problems is comparable to state-of-the-art scheduling tools.