25 research outputs found
Strategic design of competing supply chain networks for inelastic demand
A model for designing the network of a new entrant supply chain under inelastic demand and in the presence of pre-existing competing chains is proposed. These supply chains provide an identical product for a market area. The model considers the location of distribution centres and retail outlets on a discrete set of potential locations. The assumptions of the model are: (1) static competition between the new and pre-existing chains and (2) a probabilistic customer behaviour based on an attraction function depending on both the location and the quality of the retailers. This model also incorporates the impact of the facilities’ location decisions on the operational inventory and shipment decisions. The resulting model is formulated as a mixed integer non-linear programme (MINLP). To solve the MINLP it is transformed to a linear one. We illustrate the model, discuss the results of a real-world case, and investigate the effectiveness of the proposed algorithm using randomly generated examples.
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Admission, discharge, and transfer control in patient flow logistics: Overview and future research
Patient flow logistics involves managing and coordinating the movement of patients within a healthcare system. It aims to optimize the patients’ flow from their arrival to discharge or transfer, ensuring efficient and effective use of resources while minimizing delays and bottlenecks. Key components of patient flow logistics include capacity planning, resource allocation, appointment scheduling, and notably, admission, discharge, and transfer control. Our focus is on admission, discharge, and transfer control policies, which manage and regulate the flow of individual patients into and out of various facilities delivering care. We review a selection of 37 analytical, empirical, and experimental papers in this area published in leading operations research, operations management, and medical journals. These papers are categorized based on the specific department they target and the type of policies they consider. In particular, we identify: (i) four types of policies for intensive care units, (ii) three types of policies for emergency departments, and (iii) four types of policies for general wards. For each paper, we provide an overview of the research questions, formulations, solution methodologies, and results. This comprehensive review culminates in identifying future research directions for academics in this field
Concerns About Verbal Communication in the Operating Room: A Field Study
Objective: To assess verbal communication patterns which could contribute to poor performance among surgical team members in an operating room. Background: There exist certain challenges in communication in health care settings. Poor communication can have negative effects on the performance of a surgical team and patient safety. A communication pattern may be associated with poor performance when the process of sending and receiving information is interrupted or the content of conversation is not useful. Method: This cross-sectional field study was conducted with 54 surgical teams working in two Iranian hospitals during 2015. Two observers recorded all verbal communications in an operating room. An in-depth assessment of various annotated transcripts by an expert panel was used to assess verbal communication patterns in the operating room. Results: Verbal communication patterns which could contribute to poor performance were observed in 63 of the surgeries, categorized as communication failures (17 events), protests (23 events), and irrelevant conversations (164 events). The anesthesiologists and the circulating nurses had the most concerning communication patterns. The failure of devices and poor planning were important factors that contributed to concerning patterns. Conclusion: Concerning patterns of verbal communication are not rare in operating rooms. Analyzing the annotated transcripts of surgeries can conduce to identifying all these patterns, and their causes. Concerning communication patterns can be reduced in the operating room by providing interventions, properly planning for surgeries, and fixing defective devices. Application: The method used in this study can be followed to assess communication problems in operating rooms and to find solutions. © 2019, Human Factors and Ergonomics Society
Crack resistance of fiber-reinforced asphalt mixtures: Effect of test specimen and test condition
The effect of some important testing conditions including test specimen (SCB and ENDB), fracture mode (I and II), loading rate (0.5, 1.0, and 5.0 mm/min), and temperature (−5°C, −15°C, and −25°C) is evaluated on fracture toughness of asphalt material containing different percentages of fibers (0%, 0.025%, 0.05%, and 0.1% of unit weight). The experimental and numerical results show that the addition of 0.025%, 0.05%, and 0.1% of the polyolefin–aramid fiber in asphalt mixture increases the fracture toughness of the control mixture by about 8%, 17%, and 23% in pure mode I and 7%, 16%, and 24% in pure mode II, respectively; which are among the most promising enhancements compared to other fibers. Results also reveal that fracture toughness at mode I obtained from the SCB and ENDB specimens is similar. However, the mode II fracture toughness obtained from the ENDB specimen is about 12% higher than the corresponding value obtained from the SCB specimen