Modified goal chasing for products with non-zero/one bills of material

One goal of the Toyota production system is a level usage of parts in assembly. To this end Toyota developed a ‘goal chasing’ algorithm for sequencing vehicles in its assembly plants. Since the goal chasing method 1 was computationally too burdensome for most real-world applications, Toyota developed a faster version called the ‘goal chasing method 2.’ While this modified version performs well in automotive assembly for which it was designed, it cannot sequence products with non-zero/one part requirements. For example printed circuit boards have non-zero/one product-part usage matrices. These and other electronic products can have any number of a particular chip, resistor, capacitor, or other electronic component. Hence the product-part usage matrix for these electronic products is not zero/one, and the goal chasing method 2 cannot be used. The authors present another modification of the goal chasing algorithm that is faster than Toyota’s goal chasing method 2, and can sequence products with non-zero/one product-part usage matrices.