Optimization of thermal process scheduling in plants producing canned food is of great interest because canning is a dominant operation within the food processing sector. Batch processing has been widely practiced but scarcely analyzed in the context of plants producing canned food. The objective of this research study was to solve the problem of optimizing scheduling for the case where given amounts of different canned food products, with specific quality requirements, would be sterilized within a minimum plant operation time. The proposed solution is based on simultaneous sterilization implementation, using the revisited general method (RGM) procedure for process calculations, and developing a mixed integer linear programming (MILP) model to optimize autoclave scheduling with the purpose of minimizing plant operation time. In order to maximize the output from a specific plant processing different products and container sizes, isolethal processes were identified for various products/containers from which a common set of process conditions could be chosen for simultaneous sterilization of different product lots in the same retort. An example involving the sterilization of 16 different products was solved to illustrate the MILP model developed here. The methodology proposed here is of special relevance to small and medium size canneries, normally processing many different products at the same time. (c) 2008 Published by Elsevier Ltd.