An ontology for integrated planning and scheduling systems with hierarchies

Abstract

In this study, an ontology is proposed for hierarchical detailed scheduling and planning systems. By using this ontology, planning and scheduling problems at different levels can be modeled. A complete system which considers long term planning if it includes detailed information like it is in short term planning takes a lot of time and is hard to solve in many cases. Due to this reason it is beneficial to divide the complete problem into sub problems which leads to hierarchical planning systems. Main elements of the hierarchical planning system are bucket based capacity planning and continuous time advanced planning and scheduling. Bucket based capacity planning is the long term planning element in which tactical, strategic decisions are taken and continuous time advanced planning and scheduling is the short term planning item in which operational decisions are taken. Existing of hierarchy planning between bucket based capacity planning and continuous time advanced planning and scheduling brings along necessity for aggregation between hierarchical planning system elements. In a hierarchical planning system , there is an aggregation from base level to top level element of the hierarchy. Different types of aggregation which exist in real life applications are studied in this work. Also,in order to show that the ontology proposed in the study is applicable to modeling real life problems, integration scenarios between plan and scheduling for companies from different sectors are modeled.