| Japanese manufacturing techniques such as Just-in-Time have brought to the forefront the inherent advantages of a flexible work force. The flexible work force presents new opportunities for operating assembly lines, including the possibility of manning a line with fewer operators than stations.; A method for determining a flexible work force assignment and buffer capacity that operates at or near minimum cost is presented. The method, OFRO (organizing flexible, rotating operators), allows an assembly line to operate with fewer operators than stations.; A research experiment was designed to study the relationship between specified design factors in an assembly line operated using OFRO and the system response as measured by average inventory, average number of operator movements per unit of product, and the direct labor time. The levels of factors in the research experiment were selected to represent a wide range of typical operating conditions of industrial assembly lines. Simulation was employed as a modeling tool when it was not possible to determine the value of the system responses by direct calculations.; A cost per unit expression was developed for use as the selection criterion in selecting the optimum design factors, the buffer capacity and the number of operators to service OFRO assembly lines. The OFRO experiment revealed that, in terms of performance characteristics, it was possible to partition possible numbers of operators for OFRO assembly lines into two broad categories. It was also found that, in terms of cost per unit, numerous possible numbers of operators can be eliminated from consideration. In addition, for small values for time required to move, a single optimum number of operators could be identified regardless of the values for inventory carrying cost and direct labor cost. As the time required to move increases, the number of operators to assign to the line approaches N, the number of stations on the line. |
