S-DBR於MTO環境應用的強化

Abstract

Eli Schragenheim & H. William Dettmer 於2000年，提出了簡化型限制驅導式排程法(Simplified Drum-Buffer-Rope, S-DBR)的概念，主張市場需求為系統的主要限制，認為只要依據產能受限資源(Capacity Constrained Resource, CCR)的已規劃負載(Planned Load, PL)，建立良好的接單、投料及優先順序管理之機制，就不需要作CCR排程，大大地降低生產管理的複雜度，且經過6、7年的發展與實際執行，Schragenheim又於2006年提出更細部的S-DBR操作方法，同時亦指出S-DBR依然具備DBR所擁有的優點，並且可以滿足訂單交期績效(Due Date Performance, DDP)的目標。因此本研究藉由邏輯推論、Job Shop遊戲與模擬，針對Schragenheim最初的假設條件進行驗證，結果指出S-DBR可以有效地使訂單順利達交。然而，實務上仍有其他不同的生產環境，所以為了要確定S-DBR的可行性，以及解決實務上對S-DBR執行的疑慮，本研究進而延伸探討(1)單一CCR位置在製程前、後段，對訂單交期的影響；(2)CCR漂移的影響；(3)訂單批量問題；(4)訂單插單；以及(5)迴流生產環境等議題，於透過研究驗證後，確認S-DBR適用於各種不同的生產環境。另外，本研究為強化S-DBR對訂單交期的緩衝保護與競爭力，亦提出相關的調整方法，增加S-DBR回應市場需求變化與生產環境變異的能力。

In 2000, Eli Schragenheim and H. William Dettmer raised the idea of Simplified Drum-Buffer-Rope (S-DBR). They claimed that the market demand was the constraint of production system. They considered that there was no need to do the capacity constrained resource (CCR) scheduling if we could obey the CCR’s Planned Load (PL), which included well-organized confirm orders, release orders and priority management. That would make production management become easier. After developing and practicing for six or seven years, Schragenheim brought up the implementation of S-DBR more practically in 2006. He also pointed out that S-DBR still kept the advantages of DBR, and it could satisfy the Due Date Performance (DDP) at the same time. In this way, this research tried to verify Schragenheim’s assumption originally by reasoning, Job Shop game and simulation. The result showed that S-DBR could make the orders finished in time effectively. However, there are other production environments practically. In order to make sure the feasibility of S-DBR and figure out some doubts on S-DBR, this research discussed five issues further; inclusive of (1) the position of CCR’s influence on due-date among manufacturing process, (2) the influence of CCR drift, (3) batching, (4) order inserting, and (5) reentry flow environment. Furthermore, to enhance the protection and competency on due-date of S-DBR, this research also raised some ways to reinforce the ability of S-DBR when facing the variety of market demand and production environment.