40 research outputs found
Agribusiness supply chain risk management: A review of quantitative decision models
Supply chain risk management is a large and growing field of research. However, within this field, mathematical models for agricultural products have received relatively little attention. This is somewhat surprising as risk management is even more important for agricultural supply chains due to challenges associated with seasonality, supply spikes, long supply lead-times, and perishability. This paper carries out a thorough review of the relatively limited literature on quantitative risk management models for agricultural supply chains. Specifically, we identify robustness and resilience as two key techniques for managing risk. Since these terms are not used consistently in the literature, we propose clear definitions and metrics for these terms; we then use these definitions to classify the agricultural supply chain risk management literature. Implications are given for both practice and future research on agricultural supply chain risk management
Robust and resilient strategies for managing supply disruptions in an agribusiness supply chain
Agribusiness supply chains involve more sources of uncertainty than typical manufacturing supply chains due to attributes such as long supply lead-times, seasonality, and perishability. Therefore, it is critical but challenging to mitigate risks in agribusiness supply chains. However, the extant literature includes limited quantitative research on robust and resilient strategies for agribusiness supply chain risk management, particularly when perishability is explicitly modeled. In this paper, we investigate the effectiveness of a mixed set of robust and resilient strategies for managing rare high-impact harvest time and yield disruptions. We develop a two-stage stochastic programming model, which integrates an exponential perishability function, to conduct our analysis. The model maximizes the expected profit by selecting optimal risk management strategies and making tactical supply chain planing decisions. The model is applied to a numerical case study of a real-world kiwifruit supply chain. The results suggest that a mixed combination of robust and resilient strategies are most effective for mitigating supply-side disruption risks. Furthermore, as perishability increases, risk management strategies provide a greater relative improvement in the expected profit
A Practical Scheduling Method for Multiclass Production Systems with Setups
Consider a multiclass production system where many job classes share a single server and a setup time is incurred whenever the server changes class. This paper presents a simple method for scheduling these systems that performs well, not only with respect to mean waiting time, but also with respect to waiting-time variance and the outer percentiles of waiting time. The scheduling method is dynamic and uses the ages of items in each queue, as well as the queue statistics, to decide which queue to service next.heuristics, changeovers, queueing, polling, manufacturing
Rotating the medical supplies for emergency response: A simulation based approach
Serious expiration problems exist in national medical reserves prepared for emergency response. One alternative to reduce expiration is to rotate the reserve to hospitals so products can be used for day to day operations. Yet, rotation incurs extra handling costs and needs to be combined with hospitals\u27 ordering decisions. This decision process is complex and involves various sources of uncertainty. In this paper, we use discrete-event simulation to model the rotation of the reserve in combination with the hospitals’ inventory management, and combine it with optimization to search for the optimal rotation policy. With simulation experiments, we evaluate the performance of rotation policies and analyze the impact of emergencies, multiple hospitals with fixed costs, perishability in hospitals, and lead time. Simulation results highlight the different impact of these factors on the rotation performance, and make suggestions to address these concerns. It is also observed that, while rotation could generate significant cost savings, it is not always optimal to totally eliminate expiration