考慮外包價格及彈性之產能規劃

Abstract

在變化莫測的大環境下，客戶的需求急劇變化，常有淡旺季之別。由於需求的不確定性，造成產能規劃上的困難。因此，為避免淡季時產能閒置過多，固定設備投資過多造成固定資產金額太大，使得每股盈餘變少，不利於股東投資，企業除自有機台外，當旺季產能不足時，可委外生產。因此，製造商的產能包含自有產能及外包產能。自有產能屬固定產能，外包產能可視為變動產能，以因應客戶需求的變化。

本研究考慮某一製造商其生產環境為訂單性生產，有一家固定合作的代工廠。假設該製造商受景氣循環的影響，淡季及旺季產能需求差異相當大，且已知其機率分配。本研究假設旺季外包工廠願意提供之產能與製造商淡季時的下單量相依，以最小化規劃期內期望總成本為目標，構建產能規劃模式，以決定最佳自有機台購置量及淡季最佳外包機台租用時數。隨之，探討在不同外包條件下，各類成本的變化。最後以一案例說明此產能規劃模式。

Facing customers’ demands rapid change, manufacturer will be partially outsourcing to deal with customers’ fluctuating demands and to minimize its expected production cost In this study, given customers’ demand distribution functions of peak season and off-peak season, we develop a capacity planning model for a make-to-order manufacturer to determine its owned capacities and rented capacities provided by a outsourcing firm.. In this model, we assume that at peak season the rented capacities has an upper bound given by the outsourcing firm based on manufacturer’s ordering quantities of off-peak season, and manufacturer should place his order to the outsourcing firm before his customers demands are actually determined. Then , we solve this model with Mathematica software. Finally, an example is given to illustrate this model.