In this paper, we develop scheduling system under MTO (Make-To-Order) Production and implement it to real application. Generally, scheduling system is regarded as company specific problem such that the required business logic might be different within a same industry. The differences are caused by different constraints of each company requirements. Company specific algorithms are commonly employed using rule-base or heuristic procedure. Based on these characteristics, heuristic procedure are developed and implemented for developing MES (manufacturing execution system). The proposed approach are applied to real industry and proved as an efficient approach in terms of practical views.