DaimlerChrysler AG

Goals and Motivation Recently, a flexible manufacturing system has been introduced in one of DaimlerChrysler's business units. This flexible manufacturing system considerably outperforms traditional transfer lines, both in terms of robustness against break downs of single machines and in terms of flexibility. Flexible manufacturing systems of this type, however, also constitute a challenge to the planning of these systems. Essentially, this is because flexibility introduces an additional new variable into the planning process and, thus, makes the optimization process much harder. This additional variable is the extent to which the capabilities of the machines overlap. The higher the redundancy in the machine operations, the more robust is the overall system against break downs of single machines. Redundancies in the machine operations, however, may rise investment.

This tradeoff is too complex to be solved by a human planner. In a realistic setting there are over 1018 different ways of distributing operations over machines, each single one being a potential candidate for a happy tradeoff. OffWest was set up to develop a method which makes it possible to solve this tradeoff automatically. Approach OffWest developed a method for finding proper tradeoffs in the planning of flexible manufacturing systems. Not only is this method mathematically well founded, but it makes it also possible to solve the tradeoff automatically. The key technology here is constraint programming. In particular, special constraints over integers and finite sets are employed. The constraint-programming system Mozart/Oz was chosen as an implementation platform.