Estimating analytically the capacity of batch plants with shared equipment: a yoghurt plant case study

Abstract

Estimates of maximum production capacity in food plants are required when planning, scheduling, debottlenecking or optimizing manufacturing efficiency. With the exception of very simple plants and process routings, analytical methods for calculating a plant's capacity are, in general, lacking. In this paper, a novel algorithm is presented for calculating analytically the minimum cycle time and capacity of batch processes with equipment shared across overlapping process steps. The algorithm explores alternative configurations with respect to the use of shared equipment across batches and selects the one that minimizes the cycle time. The implementation of the algorithm is demonstrated with the use of a yoghurt production process whereby the same vessels are used both for the fermentation step as well as the storage of the final product before feeding the filling machines. The optimal cycle time of the yoghurt process is determined by the algorithm and the corresponding maximum capacity is calculated.