A major problem faced by many industries like sheet metal, garment, foot-wear, shipbuilding etc., is that of the stock layout. Stock layout problem is nothing but allocation of parts on to the stock sheet. An efficient stock layout can reduce material waste to a minimum, thereby reducing the product cost. In industries, stock layout has always been carried out manually and is followed even today. This procedure becomes tedious and time consuming when the number of parts to be nested is large with a variety of shapes. Nowadays, computer-aided stock layout techniques are becoming more popular because of their ability to produce better results in a lesser time. In this article, two heuristics: (a) complementary area heuristics and (b) modified area heuristics, have been developed to carry out the stock layout of rectangular parts.

An important task in many industries such as ship building, sheet metal, aerospace, glass, garment and foot wear, is to cut two-dimensional shaped parts from a large metal sheet, with minimum wastage of the sheet material. Traditionally, mock models or templates have proved to be useful in laying out the strip stock to obtain maximum economy. In this method, the optimal layout is obtained by arranging the templates in various orientations. Material utilization in the final layout purely depends on the skill and experience of the individual, carrying out this task.

Computer aided optimization techniques provide the optimal solution to the stock layout problem using integer [1], linear [2] and dynamic programming [3],[4]. But it becomes computationally infeasible to solve the above equation when the number of parts to be nested is large, as the number of variables involved increases. In view of the above limitations of the optimization techniques, several problem-specific heuristics [5]-[9] have been developed. These heuristic techniques adopt a fixed deterministic rule, and follow a sequence dependent approach to solve the nesting problem. This reduces the computational efforts substantially, though the final results obtained are sub-optimal.

Computer-aided Stock Layout of Rectangular Sheet Metal Parts, sheet metal, garment, foot-wear, shipbuilding, efficient stock layout, various orientations, optimization techniques, maximum economy, Material utilization, problem-specific heuristics.