A MIXED INTEGER PROGRAMMING-MODEL FOR OPERATOR CYCLIC WALKING PATTERN DEVELOPMENT IN GT CELLS

A class of cells where each cell is staffed with one or more operators is examined. The task of operators is to load parts into machines, to unload parts, and to transport parts between machines. For a given workload, we show that cell throughput is a function of the sequence of operations (loading, unloading, walking, waiting) that operators must attend to carry parts through the cell, and a proper choice of the sequence results in more than a 2-fold increase in cell throughput. We define the operator walking pattern problem as the problem of determining the order of these operations. A state transition diagram is developed to analyze and gain insight into this problem. Operator cyclic walking patterns are then defined. A mixed integer programming model is developed to find the optimal operator cyclic walking pattern for real GT production problems.