In recent years, manufacturing industries are required to provide various kinds of products in a short time while reducing burden on the environment. To achieve such requirement, optimization techniques incorporated with ICT are attracting a rising attention. In sheet metal processing, reducing wastes of material and managing production schedule are considered to be very important for the efficient manufacturing. To work with these problems, we attempt to simultaneously minimize wastes of material and total tardiness through nesting and scheduling. The nesting and scheduling in sheet metal processing are affected with each other and there occurs certain conflicts in their decisions. For entire efficiency of manufacturing activities, therefore, they should be decided through managing trade-off between them. Under such understanding, in our previous study, we proposed an integrated method of nesting and scheduling. This method determines a schedule under the condition that the operational sequence of punching process as the first process of sheet metal processing is fixed. In order to realize more efficient manufacturing, in this paper, we have included the punching process in our consideration. Then, this study has proposed a hybrid heuristic approach to the scheduling problem of sheet metal processing. Genetic algorithm, dispatching rule and local search technique are applied to create a schedule together with a bottom left algorithm for nesting. Finally, in order to validate the effectiveness of the proposed method, we implemented prototype of nesting scheduling system and carried out a few computational experiments.

As precut-process lumbers are packed and transported to the construction site, it is necessary to determine the packing style in consideration of the balance of the center of gravity, the ease of picking at the construction site, and the efficiency of the transportation. In our previous study, we proposed a rule-based stacking algorithm to determine the packing style of rectangular lumbers from the bottom side, but it was necessary to take into consideration the relationship between the upper and lower lumbers for preventing the inclining or dropdown the lumbers. In this study, we determine the packing style from the top side to simplify the relationship between the upper and lower lumbers. The effectiveness of the proposed method was validated through computational experiments.

The precut-processed lumbers are carried from a precut factory to a construction site after cutting in a precut factory. To enhance the construction efficiency in the construction site, the precut-processed lumbers should sort in the order of the usage. On the other hand, for the efficiency of transportation, it is necessary to lower the height of the packaging lumber. In this research, therefore, we propose a heuristic method for stacking lumbers. In this method, we determine the position of lumbers without inclining while inserting supplement lumbers, according to the order of the usage of them.

To reduce the inventory of products for Tsukudani factories, we propose a production planning method considering the constraints of the production process that consists of cutting, burning, boiling, and packaging. The proposed method includes demand forecasting based on shipping record, requirements planning, and capacity planning. Finally, to validate the effectiveness of the proposed method, we implemented a prototype system and performed computational experiments.

Rectangular plate stacking problem is to determine the position of the rectangular plate in the designated area for minimizing the stacking height. In this study, we propose a heuristic method for solving the rectangular plate stacking problem. In our method, we combine the bottom left algorithm and the rule-based balancing algorithm is applied in order to decide the position of rectangular plates without plates falling down to the lower stages. The effectiveness of proposed method was validated through computational experiments.