Using operational research methods to improve decision making in Canada's blood supply chain

加拿大血液服务公司（CBS）花费10亿美元为加拿大人提供安全的血液供应。由于限制成本的压力越来越大，有必要提高血液供应链的效率。血液制品易腐烂，因此容易浪费。管理血液库存是困难的，因为订购决策必须考虑库存的年龄。历史上，关于血液供应链管理的文献主要集中在单个供应商或消费者的红细胞（RBC）库存政策上。然而，由于提议改变红细胞（RBC）的存储限制，端到端供应链模型最近成为全球研究人员和血液机构感兴趣的话题。目前，我们正在制定一个代表加拿大十个区域血液分配网络的建模框架。我们正在进行的工作产生了一种方法，在区域血液分配网络供应链模型的范围、细节和可重用性方面向前迈出了重要一步。我们建议扩展我们的区域建模框架，以解决血液供应链管理中的四个重要问题。1)红细胞保质期缩短的影响：最近的研究对红细胞储存后的安全性提出了质疑。然而，缩短保质期可能会造成短缺或大大增加产品浪费。因此，有必要确定RBC保质期缩短的影响。我们将使用我们的区域建模框架来评估10个CBS血液分销网络中RBC的较短保质期。通过评估较短的保质期对一系列问题的影响，我们可以概括出结果，并框定正在进行的关于输血新血液的成本和收益的辩论。2)非FIFO发放政策：易腐血液制品的最优政策遵循先进先出（FIFO）规则。然而，加拿大皇家银行保质期缩短的幽灵重新燃起了人们对非先进先出政策的兴趣。最近出现了一些描述非fifo发行的论文。该文献的一个显著特征是分析的单一范围，仅关注医院的发行政策；关于非fifo发布策略如何在网络中工作的更广泛背景尚未进行调查。我们将扩展我们的框架，从网络的角度评估非fifo发行政策。3)年龄公平分配政策：加拿大各医院发放的RBC年龄并不统一。较大的工厂往往更频繁地更换库存，因此供应较旧的库存，而较小的工厂则获得较新的库存。这种做法最大限度地提高了产品在遥远地点的可用性，并降低了交付成本。然而，有人认为，这导致更频繁的输血需求和一些患者的预后较差。有必要制定发布政策，促进血液制品在整个网络中的公平年龄分配，以确保所有加拿大人都能公平获得安全有效的血液制品。4)动态库存再平衡：在加拿大，库存是在区域一级进行管理的，而血液是在区域之间有计划或临时进行的全国性资源和物资流动。CBS收集的所有RBC中约有20%在站点之间转移。目前没有研究为加拿大用于重新平衡血液库存的控制政策建立科学依据。我们将采用基于模拟的优化（SBO）方法来评估CBS分销站点之间的库存再平衡策略。该项目将有助于降低哥伦比亚广播公司的运营成本，同时促进在全国更可靠地获得所需的血液制品。

Canadian Blood Services (CBS) spends $1B to provide Canadians with a safe supply of blood. As pressures mount to constrain costs, there is a need to improve the efficiency of the blood supply chain. Blood products are perishable and thus subject to wastage. Managing blood inventory is difficult because ordering decisions must consider the age of stock. Historically, the literature on blood supply chain management has focused on Red Blood Cell (RBC) inventory policies for a single supplier or consumer. However, because of proposed changes to the storage limits of red blood cells (RBC), end-to-end supply chain modelling has recently become a topic of interest for researchers and blood agencies around the globe. Currently, we are working on a modelling framework to represent ten regional blood distribution networks in Canada. Our ongoing work has produced an approach that represents a significant step forward in terms of scope, detail, and re-usability of supply chain models for regional blood distribution networks. We propose to extend our regional modelling framework to address four important issues in blood supply chain management. 1) The impact of a shorter shelf-life for RBC: Recent studies have raised questions about the safety of RBC after storage. However, reducing shelf life would likely create shortages or substantially increase product wastage. Thus, there is a need to determine the impact of a reduced shelf life for RBC. We will use our regional modelling framework to evaluate a shorter shelf life for RBC in each of the ten CBS blood distribution networks. By evaluating the impact of a shorter shelf life across a class of problems we can generalize results and frame the ongoing debate regarding the costs and benefits of transfusing newer blood. 2) Non-FIFO issuing policies: It has been well established that optimal policies for perishable blood products follow first-in-first-out (FIFO) rules. However, the spectre of a shorter shelf life for RBC has renewed interest in non-FIFO policies. Recently, several papers describing non-FIFO issuing have appeared. A distinguishing feature of this literature is the unitary scope of analysis, which focuses only on hospital issuing policies; the broader context of how non-FIFO issuing policies would work in a network has not yet been investigated. We will extend our framework to evaluate non-FIFO issuing policies from a network standpoint. 3) Age equitable distribution policies: The age of RBC issued to hospitals in Canada is not uniform. Larger facilities, which tend to turn stock more frequently, are supplied with older stock, while smaller facilities get newer stock. This practice maximizes product availability at distant sites and lowers delivery costs. However, it has been suggested that it leads to more frequent transfusion requirements and poorer outcomes for some patients. There is a need to develop issuing policies that promote equitable age distribution of blood products across an entire network to ensure all Canadians have equitable access to safe and effective blood products. 4) Dynamic inventory re-balancing: While inventory is managed on a regional level in Canada, blood is a national resource and materials flow, either on a planned or ad hoc basis, between regions. Approximately 20% of all RBC collected by CBS are transferred between sites. No study has established a scientific basis for control policies currently used to re-balance blood inventory in Canada. We will employ simulation based optimization (SBO) methods to evaluate policies for inventory re-balancing between CBS distribution sites. This project will help to reduce operational costs at CBS while promoting more reliable access to needed blood products across the country.