Heuristic Algorithm for Scheduling of Make-to-Order Plant Factory with Considering Crops Size Variation during Cultivation

Plant factory is an environmental controlled facility which can sustain the stable crop cultivation with fast production and better quality by controlling temperature, humidity, lighting, nutrient supply and other cultivating factors. In this research, focus on production scheduling problem of ordering based (Make-to-Order) plant factory and consider size change as time past of crops. The scheduling problem was formulated as a mixed integer programming (MIP) problem. The objective function is to seek the maximum revenue of the plant factory by considering several practical operating conditions such as cultivation room space, environmental constraints, crop, due day of order. The operating conditions are formulated as constraints, and the MIP problem was solved by LINGO programming model to obtain the optimal solution. The computation time of LINGO solver is exponentially increasing when the problem domain is larger. Therefore, we propose the heuristic algorithm (HOBPFS) to solve the large size problem instance, which result show that our heuristic algorithm can indeed get good feasible solutions.