考量供給及需求不確定與延遲策略下探討正向與逆向供應鏈最佳模式

An Optimization Study of Forward and Reverse Supply Chain Models with Consideration of Postponement Strategies under Supply and Demand Uncertainties

郭祥謙(DANIEL BUDIMAN SYARIF)

指導教授 ： 饒忻

中原大學/電機資訊學院/工業與系統工程學系/博士(2022年)

https://doi.org/10.6840/cycu202201465

摘要

近年來企業利用複雜且大規模的供應鏈運作來滿足世界各地的需求，然而要在此環境下建造出相關的作業是非常具有挑戰性的，尤其是在以下所發生的事件下，如全球疫情造成供應鏈中斷、全球氣候危機與廢棄物問題等。藉此，本研究透過延遲策略的概念，發展供應鏈網路平台，來探討相關議題。儘管供應鏈的延遲問題已被討論有一段時間，但其中仍缺乏以供應鏈網路建模，結合延遲策略以探討環境問題、運營不確定性與中斷等風險的研究，更不用說結合延遲策略與逆向供應鏈之研究。因此，本研究提出考量延遲策略的供應鏈網路建模，並分為兩個部分：正向供應鏈網路與逆向供應鏈網路。研究採用混合整數線性規劃及兩階段隨機規劃兩種方法建立模型。
在正向供應鏈部分，本研究開始建構跨多層之供應網絡模式，以滿足多變化的產品需求。接著，在供應鏈網路中以模組來發展預測與延遲策略，以實現大量客製化與規劃推與拉策略。此外，模型在全球化供應鏈環境下，探討環境政策、需求與供應鏈不確定性及中斷問題。最後，發展四種預測與延遲策略優化以上情境。研究數據顯示，當平衡風險成本與作業成本時，延遲策略可以降低供應鏈的總成本；也突顯出在遵守嚴格的環境政策下，它有幫助適應波動之全球供應鏈的能力。
在逆向供應鏈部分，本研究為結合延遲策略至逆向供應鏈領域中的先驅之一。首先，以物料清單結構與回收品質，對產品回收、再製造與料料回收等作業建模。此外，制定三種不同延遲程度的預測與延遲策略，以適應預測與逆向供應鏈的作業規畫。最後，在考量供應與需求不確定與中斷下，優化逆向供應鏈以進行設施配置與流程選擇。研究結果顯示，採用正確的延遲策略可優化逆向供應鏈，可以降低逆向供應鏈的風險成本與操作成本。在高度不確定性或嚴格的環境政策下，其可在提供所需效率與反應能力上取得平衡，以改善經濟表現。此外，在逆向供應鏈實施延遲策略比沒實施延遲策略表現得更為突出，展示延遲策略可以改善逆向供應鏈系統。
總體而言，延遲提供一種全面優化的方法，可適當模擬現實世界供應鏈的各種複雜情況與大規模問題，並可進一步面對環境問題、多種不確定及供應鏈帶來的中斷。此外，在逆向供應鏈領域，延遲的實施可以協助系統的不確定性風險，改善廢棄物管理問題。本研究展示延遲策略的發展及延伸是適合處理現代供應鏈的議題，是塑造未來可持續供應鏈發展的基礎。

關鍵字

全球供應鏈網路 ； 逆向供應鏈 ； 需求不確定性 ； 供應不確定性 ； 中斷 ； 延遲策略 ； 環境政策

並列摘要

The modern business traits have urged the utilization of complex and large-scale supply chain operations to fulfill the worldwide demand. However, shaping up these operations for such a business environment is very challenging, especially in the wake of events, such as the global pandemic disruption, global climate crisis, and waste problems. This research revisits the concept of postponement strategy in developing the supply chain network (SCN) as a platform to cope with these situations. In the supply chain field, postponement has been studied for some time. However, there is still a lack of studies of SCN modeling with postponement for the purpose of addressing environmental issues, operational uncertainties and disruption, let alone, integrating postponement with reverse SCN. Therefore, this research proposes two parts of SCN modeling with postponement strategies: the forward SCN (FSCN) and the reverse (SCN) RSCN. Mixed-integer linear programming and two-stage stochastic programming are used to formulate the models in this research.
On the FSCN part, the research highlights are as follows. To begin with, this research models the operations performed across a multi-tiered SCN, to fulfil multi-variant product demands. Then, speculation and postponement (SP) strategies with modularization are developed into the SCN models to enable the mass customization and operations planning of push-pull strategy. Furthermore, the models are set under the globalized supply chain environment while addressing environmental policies, the demand and supply uncertainties, and disruption. Finally, four SP strategies are formulated into the models to be optimized by considering abovementioned points. Results show that these strategies can consistently reduce the SCN’s total cost by balancing between risk and operational costs. Therefore, it highlights postponement strategies’ capability to anticipate the volatile global supply chain environment while adhering to stricter environmental policies.
On the RSCN part, this research has become one of the pioneers in integrating postponement strategies into the RSCN research field. The highlights of the RSCN part are as follows. To start with, the RSCN is modeled to perform the takeback, remanufacturing and recycling operations of multi-variant products with BOM structure and takeback quality issue. In addition, related to the operations planning of the RSCN, three SP strategies with different degrees of postponement are developed to accommodate the forecast and RSCN operations planning. Finally, the proposed models are used to optimize the RSCN configuration by adjusting to various supply and demand uncertainties and disruptions. Results show how RSCN optimization using the right postponement strategies can mitigate the risk and operational costs. It balances required efficiency and responsiveness to improve economic performances even under high uncertainty levels or stricter environmental policies. Moreover, the RSCN performs better with postponement strategies than without, demonstrating how postponement can improve the RSCN system.
Overall, postponement allows a comprehensive optimization approach to properly model the variety of real world’s SCN problems and further address dire environmental issues, uncertainties and disruption. In addition, postponement implementation in the RSCN field can anticipate the system’s uncertainty risks while improving waste management issues. This research shows how the development and extension of postponement strategies suit the modern supply chain issues and is fundamental in shaping future sustainable supply chain development.

並列關鍵字

globalized supply chain ； reverse supply chain ； demand uncertainty ； supply uncertainty ； disruption ； postponement strategy ； environmental policies

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