Planned Man-Hour Calculation System in High-Mix Assembly Products

Abstract

Recently, factories which produce high-mix assembly products face challenges to estimate the planned man-hours accurately and automatically, for the purpose of reducing overtime hours. In factories which produce high-mix assembly products, it is difficult to estimate the planned man-hours because the number of products is small and there are few opportunities to produce similar products. In order to solve the above problems, this paper proposes an approach with the following two features. The first feature is to calculate the man-hours for each product specification by the regression analysis with the appropriate upper and lower limit values set as the partial regression coefficient as input for the actual man-hours data and product specification data for each product / process. The second feature is to regularize with an appropriate value as product specification in order to stabilize the solution even when the amount of data is small. We have applied the approach to our factory, and we proved the approach can reduce 18% of the rate of deviation between the planned man-hours and actual man-hours at a maximum compared to the case of planning experts. Therefore we have confirmed the effectiveness of the proposed system and released as a product.