Operation-time calculation device and method for calculating operation time

An operation time calculation method using operation result information from a manufacturing floor, the operation time calculation method comprising causing a computer equipped with a storage unit, an input unit, a control unit, and a display unit to function so that:

• the storage unit stores
• operation result information including at least operation process information, start date and time information, and end date and time information about each operation implemented,
• work time information including at least an assigned process, a date, and a work time per piece of equipment and per worker, and
• operation time information including at least a product type, an operation process, an initially set operation time, and an operation time conversion coefficient;
• the input unit accepts input, from a user, of parameters regarding at least an aggregation target process, an aggregation start date and time, an aggregation end date and time, and an aggregation unit period;
• the control unit performs
• a process in which an aggregation period is set based on the input aggregation start date and time, aggregation end date and time, and aggregation unit period,
• a process in which a total work time of the aggregation target process in each aggregation period is calculated by a search through the work time information, and a total operation time of the aggregation target process in each aggregation period is calculated by a search through the operation result information and the operation time information and by converting the corresponding operation time using the operation time conversion coefficient,
• a process in which an error is calculated between the total work time and the total operation time in each aggregation period, and
• a process in which the operation time conversion coefficient is changed so as to minimize the error, wherein the error ((totAT.subj−totST.sub.j)/totAT.sub.j) between the total work time (totAT.sub.j) and the total operation time (totST.sub.j) in each aggregation period (R.sub.j) is calculated, and the operation time conversion coefficient is changed so as to bring the total operation time close to the total work time in each aggregation period, thereby minimizing an average of the errors from the aggregation periods;
• and
• the display unit displays the operation time conversion coefficient, a graph comparing the total work time with the total operation time in each aggregation period before and after the operation time conversion, and the errors involved, all being obtained in the processes performed by the control unit.