Building holarchies for concurrent manufacturing planning and control in EtoPlan

The increasing versatility in order characteristics calls for planning and control systems that are able to evolve in time. Traditional hierarchical systems are usually based on a function-oriented static control structure in which all orders and products are handled similarly. Due to the dynamically changing characteristics of manufacturing environments these static control structures are not suitable anymore. Hence, a concept description and a prototype implementation for concurrent manufacturing planning and control (EtoPlan) based on multiple and temporary hierarchies (holarchies) are presented. The alternative control structure allows among other things to bridge the gap between process planning and production planning. The EtoPlan order planning method explicitly models the uncertainty in the information due to incompleteness of process planning information and shop ¯oor randomness.