Abstract
In many industries, equipment costs constitute an important proportion of overall manufacturing costs. Much of attention has paid on overall equipment effectiveness(OEE) of equipment efficiency. Much less attention was paid on the input side of efficiency. The overall input efficiency can be divided into components such as: operator efficiency, material usage efficiency, facility efficiency, etc. The research addresses the issue of determining optimal operator-machine configuration so that the ideal operator-machine assignment can be found thus the operator efficiency can be calculated as a part of overall input efficiency. Formula for optimal operator-machine configuration for single and multiple process machines are derived. Simulation models were used to verify the formula with matching product releasing times and machine utilization rate. The formula allows us to determine the best operator-machine ratio and calculate the operator usage efficiency. Data from a wafer reclaim factory were used to illustrate the calculation of equipment usage efficiency, opportunity for doubling operator usage efficiency was identified using the derived formula. Contributions of this work include: 1) Deriving a set of formula to calculate optimal operator-machine configuration and calculating the operator usage efficiency. 2) Providing an Excel-based software for easy calculation of the ideal operator-machine configuration & usage efficiency.