Stochastic Goal Programming and a Metaheuristic for Scheduling of Operating Rooms

Health care systems in Canada provide benefits to patients but have issues with costs and wait lists. Long wait lists negatively affect patients’ welfares. This in turn can increase costs because conditions can develop into more complicated ones over time. Operating rooms in a hospital are responsible for a significant portion of both costs and benefits; therefore, finding ways to use them more efficiently can reduce both the waste of tax dollars and the lengths of wait lists and can improve patients’ welfares. In this research, a stochastic weighted goal programming model is proposed to perform elective surgery scheduling under uncertainty of both surgical durations and patient lengths of stay. The model generates a Master Surgical Schedule that schedules surgical teams in operating room blocks in a way that minimizes four objectives, which are the deviations between the targeted number of surgeries and the actual number of surgeries performed, the deviations between the targeted number of hours for surgeries and the actual number of hours used for surgeries, the maximum expected number of patients in the recovery ward over the course of the planning horizon, and the difference between the maximum and minimum expected numbers of patients in the recovery ward over the course of the planning horizon. In addition, the impact of cancellations on the schedule is taken into account. A simulated annealing metaheuristic is developed to find near-optimal solutions. Discrete event simulation is used for validation and to demonstrate the system of operating rooms and recovery ward beds to relevant stakeholders in the health care sector

Minimizing food waste in grocery store operations: literature review and research agenda

Research on grocery waste in food retailing has recently attracted particular interest. Investigations in this area are relevant to address the problems of wasted resources and ethical concerns, as well as economic aspects from the retailer’s perspective. Reasons for food waste in retail are already well-studied empirically, and based on this, proposals for reduction are discussed. However, comprehensive approaches for preventing food waste in store operations using analytics and modeling methods are scarce. No work has yet systematized related research in this domain. As a result, there is neither any up-to-date literature review nor any agenda for future research. We contribute with the first structured literature review of analytics and modeling methods dealing with food waste prevention in retail store operations. This work identifies cross-cutting store-related planning areas to mitigate food waste, namely (1) assortment and shelf space planning, (2) replenishment policies, and (3) dynamic pricing policies. We introduce a common classification scheme of literature with regard to the depth of food waste integration and the characteristics of these planning problems. This builds our foundation to review analytics and modeling approaches. Current literature considers food waste mainly as a side effect in costing and often ignores product age dependent demand by customers. Furthermore, approaches are not integrated across planning areas. Future lines of research point to the most promising open questions in this field

Essays on Risk Mitigation Methods in Global Supply Chain Management

In this dissertation, we study risk mitigation methods in the area of global supply chain management. Recent economic uncertainties such as the U.S. credit and the Greek debt crises, and natural disasters such as the Japanese tsunami create a greater amount of uncertainty and risk for global supply chain operations. The goal of the dissertation is to develop new prescriptive policies for multinational corporations and global relief organizations in order to assist them in mitigating the risks present in their operating environment in an effective manner. The first essay of the dissertation investigates how a multinational corporation can effectively hedge against the exchange-rate risk by structuring and managing a supply chain in a global setting. Economic uncertainties such as the U.S. credit crises and the debt concerns in southern European countries (e.g., Greece, Italy, Portugal and Spain) call for new policies in order to operate under an increased level of uncertainty. For example, even though the Japanese Yen and the US Dollar are considered to be more stable currencies, they have exhibit significant fluctuations in recent times, putting the US Dollar at its record low against the Yen on October 24, 2011, since the Great Depression. Naturally, such exchange rate fluctuations increase the need to develop new risk mitigation policies that would assist global corporations in managing the fluctuations in their global revenues and profits. This essay provides multinational corporations with prescriptions for ways to cope with the increased amount of global economic uncertainty. It demonstrates that production hedging, defined as producing and supplying less than the firm\u27s total global demand, can be an effective policy in minimizing the negative implications of the exchange-rate risk while maximizing global profits. The second essay of the dissertation examines how a global relief organization can effectively hedge against the risk of demand uncertainty in its distribution of essential products to the areas of urgent needs. It is commonly observed that deficiencies in information infrastructure or economic instability contribute to the adversity of forecasting the need for essential supplies. This study stems from recognizing the ineffectiveness in the distribution of humanitarian aid supply in countries of need. Such distribution inefficiencies can lead to harmful consequences for many people. United Nations Children\u27s Fund (UNICEF) reports that in 2007 alone, 9.2 million children worldwide under the age of five died from largely preventable causes. It is important to recognize that many of the well-developed theories are hard to apply in these countries because of inferior infrastructure and the unstable nature of the economy and political environment. Thus, it is critical to develop new policies and insights for the managers of humanitarian organizations in order to increase the efficiency of distribution operations under uncertainty. Specifically, the second essay of this dissertation demonstrates that a relief organization can minimize the risk of shortages by strategically utilizing its limited budget on procurement and the transportation of essential supplies

Sustainable Industrial Engineering along Product-Service Life Cycle/Supply Chain

Sustainable industrial engineering addresses the sustainability issue from economic, environmental, and social points of view. Its application fields are the whole value chain and lifecycle of products/services, from the development to the end-of-life stages. This book aims to address many of the challenges faced by industrial organizations and supply chains to become more sustainable through reinventing their processes and practices, by continuously incorporating sustainability guidelines and practices in their decisions, such as circular economy, collaboration with suppliers and customers, using information technologies and systems, tracking their products’ life-cycle, using optimization methods to reduce resource use, and to apply new management paradigms to help mitigate many of the wastes that exist across organizations and supply chains. This book will be of interest to the fast-growing body of academics studying and researching sustainability, as well as to industry managers involved in sustainability management

Operational Research: Methods and Applications

Throughout its history, Operational Research has evolved to include a variety of methods, models and algorithms that have been applied to a diverse and wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first aims to summarise the up-to-date knowledge and provide an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion. It should be used as a point of reference or first-port-of-call for a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order. The authors dedicate this paper to the 2023 Turkey/Syria earthquake victims. We sincerely hope that advances in OR will play a role towards minimising the pain and suffering caused by this and future catastrophes