Abstract

With 212 locations serving a geographical area three times the size of the state of Texas, our international client has been experiencing unexpected failures in his portfolio of thousands of refrigeration units, resulting in an associated loss of $1.4 million. These losses have been attributed to lapses in food quality caused by improper refrigeration, and the adopted reactive maintenance strategy of the refrigeration units. To assist our client in complying with the cold-chain regulations of food safety and mitigate such losses, the agent-based simulation was used to model and assess the viability of two distinct massively populated Internet of Things (IoT) alternatives. The first (alternative A) involves monitoring the availability of each of the refrigeration units and signaling for the initiation of repair processes and food removal from failed units when the cooling temperature differs from a specified threshold and a more sophisticated and expensive alternative B that involves the adoption of the added capability of a condition-based predictive maintenance strategy to reduce unplanned downtime and mitigate or eliminate the causes of failure. Using historical data, a simulation of the current operations was first modeled, validated, and then augmented with capabilities to address the operational characteristics of the proposed IoT implementations. Results of financial analysis results including the probabilistic risk analyses, that account for the variations and the probability distributions of the assumption parameters, showed alternative A to be superior, with a mean net present value (NPV) of $416,703, and a modified IRR of about 18.77% exceeding the project cost of capital of 12.80% with complete certainty. The client was also advised that a 30% reduction in the acquisition cost would make investment B as viable as investment A.

摘要

我们的国际客户拥有 212 个服务点，服务的地理区域是德克萨斯州的三倍，我们的国际客户在他的数千台制冷设备组合中遇到了意外故障，导致相关损失 140 万美元。这些损失归因于冷藏不当导致的食品质量下降，以及冷藏机组采用的反应性维护策略。为了帮助我们的客户遵守食品安全的冷链法规并减少此类损失，基于代理的模拟被用于建模和评估两种不同的大规模物联网 (IoT) 替代方案的可行性。第一个（备选方案 A）涉及监控每个制冷单元的可用性，并在冷却温度与指定阈值不同时发出信号以启动维修过程和从故障单元中移除食物，以及更复杂和更昂贵的备选方案 B，其中涉及采用基于条件的预测性维护策略的附加功能，以减少计划外停机时间并减轻或消除故障原因。使用历史数据，当前操作的模拟首先被建模、验证，然后增强了处理提议的物联网实施的操作特征的能力。财务分析结果，包括概率风险分析，考虑到假设参数的变化和概率分布，表明备选方案 A 更优，平均净现值 (NPV) 为 416,703 美元，修改后的内部收益率约为 18.77%，超过了 12.80% 的项目资本成本完全确定。客户还被告知，购置成本降低 30% 将使投资 B 与投资 A 一样可行。