Reactive operation managenlent -Predictive, reactiveand proactive schedulingContinuous, steady improvement of manufacturing operation management from information technology (IT) perspective is a key requirement to manufacturing enterprises competing under the pressure of changing market demands.Manufacturing systems often operate in complex environments rife with uncertainty. The growing complexity of manufacturing operation management lies in the nonexpected tasks/events, nonlinearities, and a multitude of interactions which arise when attempting to control various activities in dynamic shop floors. This complexity and uncertainty seriously limit the effectiveness of conventional control and scheduling approaches. Reactive/proactive systems of shop floor control and scheduling with adaptive behaviour that is ensured by some embedded learning capability and based on real-time monitoring of executed processes, represent the viable alternative.The broad goal of manufacturing operation management, like other resource constrained, multi-agent planning/scheduling problems, is to achieve a co-ordinated efficient behaviour of manufacturing in servicing production demands while responding to changes in shop floors in a timely and cost-effective manner [164]. Operation scheduling, viewed a major issue of manufacturing operation management, has remained a complex co-ordination task despite the recent trends and efforts towards a structural rationalisation in manufacturing (e.g., through the implementation of group technology and JIT strategies). Quality of the operation scheduling process generally has a profound effect on the overall factory performance. Advance generation of the factory schedules is considered central to co-ordinate manufacturing activities in order to meet some organisational objectives, usually the three-pronged objective of producing parts of higher quality at lower cost within a shorter lead time. The generation of advance (predictive) schedules is also demanded for anticipating potential performance obstacles (e.g., resource contention), and for timely assuring physical preconditions (availability of all the needed resources, presetting of processes) to the execution of scheduled manufacturing activities, in order to minimise the disturbing effects on the overall manufacturing system operation.