本研究主要是要探討在一個紡織廠中染整段生產排程的問題。染整段的生產排程的決策者，必須面對下列複雜的決策情境：(1)每項成品是由胚布等級與色水號組合而成，因此染整製令可能有許多種產品規格；(2)在每部染整機台，並非可以生產所有的產品，故部分產品僅能指派到某一些特定的染整機台；(3)製令排序的順序，可能因色水號相近的程度而會影響到兩張相連的染整製令間換線的時間，因此本研究為一組合性最佳化(Combinatorial Optimization)之問題。本研究提出一個兩階段式的啟發式演算法進行求解：在第一階段，運用下列兩個程序來得到初始排程：(1)運用貪婪法則將染整製令指派到其中一部染整機台上；(2)調整指派到各染整機台染整製令的排序。在產生初始排程後，估計其總成本。在第二階段，透過各部機台內染整製令的挪動或互換，企圖降低整體生產排程發生的總成本，以搜尋更適當的解。本論文的研究成果可以協助紡織廠染整段的生產排程決策者一套有效的決策支援，求解成本效益更顯著的生產排程，進而改善紡織廠之經營績效。 This study is concerned with solving the production scheduling of dye and finishing in a textile firm. The production manager in the department of dye and finishing department has to face the following complicated decision-making scenario: (1)Each manufacturing order of dye and finishing might contain many product specifications because one has to designate a particular combination of the grade of gray cloth and colors. (2) Some manufacturing order can be produced on a subset of dyeing machines since some dyeing machines are not able to process certain manufacturing orders. (3)The setup time will depend on the required colors of two consecutive manufacturing orders. We are interested in obtaining an optimal scheduling of the manufacturing orders assigned to all the dyeing machines, which is a combinatorial optimization problem. In this study, we propose a two-staged heuristic for solving this problem. The first stage of the proposed heuristic employs the following two procedures to obtain an initial production schedule: (1) a greedy procedure that assigns the manufacturing orders to one of the machine. (2) another simple procedure that rearranges the sequence of the manufacturing orders assigned to the same machine and estimates the total cost incurred from the initial production schedule. In the second stage, the proposed heuristic tries to reduce the total cost of the best production schedule using a swapping and an exchanging subroutines that change the sequence and the assigned manufacturing orders on each machine. The proposed heuristic may serve as a decision support tool for the decision makers in the department of dye and finishing department so as to improve the efficiency of the production systems in textile industry.
