Conserving water by optimizing production schedules in the dyeing industry

Industrial dyeing processes generate a huge amount of wastewater, because the production lines have to be washed out each time when the dye changes. We propose an algorithm for the optimization of production schedule. It aims to reduce the production time and the amount of freshwater consumption by optimization the groups orders according to color. Furthermore, we develop software based on the genetic algorithm and implement it in a Chinese company. We optimize the schedules in three months of the case company and compare its output to actual data. The results show that compared to the original manual schedules, the optimized schedules cut production time by 10–15%, reduce freshwater consumption by 20–30%, and reduce wastewater generation by about 20%.