Summary Concerning Theoretical Developments
Lot sizing is a major decision taken during the planning of production of various products in process and manufacturing industries. The lot sizing problems can be classified into continuous lot sizing problem (economic lot scheduling problem) and dynamic lot sizing problem. The time scale considered is continuous and infinite in the continuous lot sizing problem, whereas a discrete time scale is considered in dynamic lot sizing problems. The dynamic lot sizing problems are further classified into uncapacitated and capacitated lot sizing problems based on their capacity restrictions. The capacitated lot sizing problems are further classified into small bucket and big bucket lot sizing models depending upon the number of setups that are allowed in a given time period. The discrete lot sizing and scheduling problem (DLSP), continuous setup lot sizing problem (CSLP) and the proportional lot sizing and scheduling problem (PLSP) come under the small bucket lot sizing models, and the capacitated lot sizing problem (CLSP) comes under the big bucket lot sizing model.