The apparel industry faces global competitions in recent years. On-time delivery and cost-efficient production are the two most important issues for today apparel manufacturers. Therefore, a production scheduling system becomes a vital tool. For most apparel manufacturers, sewing operations are the bottleneck processes. Thus, this study focuses on the production scheduling problem of the sewing operation. A two-stage approach is proposed to solve the problem and each stage handles one objective. In the first stage whose objective is to minimize maximum lateness, we proof that multiple-production-line sewing-operation scheduling problem can be converted into a single-machine problem. By using preemptive EDD dispatching rule, an optimal schedule can be generated. In the second stage, based on the result of the first stage, we formulate a mixed integer program to minimize the manufacturing cost, which is the second priority objective. Computer experiments are conducted to validate the proposed approach and show that a near-optimal schedule can be obtained within a reasonable computation time.

近年來成衣業面臨全球化市場競爭愈演愈烈的趨勢，對於現今成衣生產者而言，準時交貨以及有效降低生產成本，便成了兩項最重要的課題，因此，一套生產排程系統將是一個不可或缺的工具。絕大多數成衣製造流程之瓶頸皆為車縫製程，故本研究專注於成衣廠車縫製程的生產排程，提出一個兩階段方法來求解本問題，且兩階段各有一個不同的目標式。第一階段之目標式為最小化最大延遲時間，本研究證明出多條生產線之車縫製程排程問題能被轉換為單一機台問題，再利用一個派工法則（可插位最早交期法則）即可得到本階段之最佳排程；第二階段則是基於第一階段之結果，建構一個目標式為最小化生產成本之混合整數規劃，進而得到一最佳排程。經實驗驗證本研究方法之成效，顯示本方法可在合理之求解時間內獲得一近似最佳解。

CPLEX, 2001. Reference Manual. ILOG Optimization.
Horn, W. A., 1974. Some simple scheduling algorithms. Naval Research Logistics, 21 (4), 177-185.
Jacobs-Blecha, C., Ammons, J. C., Schutte, A. and Smith, T., 1998. Cut order planning for apparel manufacturing. IIE Transactions, 30 (1), 79-90.
Lee; L. H., Abernathy, F. H. and Ho, Y. C., 2000. Production scheduling for apparel manufacturing systems. Production Planning and Control, 11 (3), 281-290.
Pinedo, M. L., 2005. Planning and Scheduling in Manufacturing and Services. New York: Springer Science.
Rose, D. M. and Shier, D. R., 2007. Cut scheduling in the apparel industry. Computers and Operations Research, 34 (11), 3209-3228.
Taiwan Textile Federation, December 2007, http://news.textiles.org.tw/ .
Tomastik, R. N., Luh, P. B. and Liu, G.., 1996. Scheduling flexible manufacturing systems for apparel production. IEEE Transactions on Robotics and Automation, 12 (5), 789-799.
Wong, W. K., 2003. Optimisation of apparel manufacturing resource allocation using a generic optimised table-planning model. International Journal of Advanced Manufacturing Technology, 21 (12), 935-944.
Wong, W. K., Leung, S. Y. S. and Au, K. F., 2005. Real-time GA-based rescheduling approach for the pre-sewing stage of an apparel manufacturing process. International Journal of Advanced Manufacturing Technology, 25 (1), 180-188.
Wong, W. K., Kwong, C. K., Mok, P. Y., Ip, W. H. and Chan, C. K., 2005. Optimization of manual fabric-cutting process in apparel manufacture using genetic algorithms. International Journal of Advanced Manufacturing Technology, 27 (1), 152-158.
Wong, W. K., Mok, P. Y. and Leung, S. Y. S., 2006. Developing a genetic optimisation approach to balance an apparel assembly line. International Journal of Advanced Manufacturing Technology, 28 (3), 387-394.
Wong, W. K., Kwong, C. K., Mok, P. Y. and Ip, W. H., 2006. Genetic optimization of JIT operation schedules for fabric-cutting process in apparel manufacture. Journal of Intelligent Manufacturing, 17 (3), 341-354.