Research On Constraint-based Modern Scheduling System

In the real world, combinatotial optimization problems are ubiquitous, most of which are NP completed problems. So resolving this kind of problem efficiently has great research value in theory, and especially resolving those problems, such as resource allocation, job shop scheduling, timetabling, and routing, still has very important realism significance and commerce significance. Scheduling is a kind of important combination optimization question, and is for realize some goal but to the resources implementation time assignment which uses together. The scheduling and the optimization have close relationship. The goal of scheduling is optimization, but scheduling also is the optimized one kind of concrete manifestation form. Along with the complex production processing craft and the advanced processing technology, the modern scheduling displays below the characteristic: the high complex (modeling complex and calculating complex), duplicate board multi-goals and the dynamic randomness.In the past, solvents comprise handwork or tradition methods in operational research. Their abuse is strongly depending on the structure of the problems, and generating irrationality solution. In the artificial intelligence field, problem resolving system regards combinatotial optimization problems as the primary research content all along. But these kinds of problems always require searching through a possibly exponentially sized solution space in order to find a good or optimal solution to the problem. To obtain reasonable efficiency, the constraints must be used to prune the search space, viz., adopting the constraint resolving technology to resolve combinatotial problems.Constraint is an extensive concept. Intuitively, a constraint is viewed as restriction in possibility space. Mathematic constraint (e.g. X+Y>Z) is simply a logical relation among several unknowns (variables X, Y, Z), each taking a value in a given domain. A constraint thus restricts the possible values that variables can take. Formally, a constraint is simply a logical relation among several unknowns, each taking a value in a given domain. Constraints are used to model the behavior of systems of objects in the real world by capturing an idealized view of the interaction among the objects, this called constraint modeling. It is the category of constraint programming to simplify a real world situation into a system of constraints about idealized objects, and use this system...