BOHR International Journal of Operations Management Research and Practices

Application of tabu search, TS, to solve a flow shop scheduling problem with changeover times in operations: A case study

Phong Nguyen Nhu — 2024-01-05

Flow Shop Scheduling (FSS) Problems are NP-hard combinatorial optimization problems. It is quite difficult to achieve an optimal solution for FSS problems with mathematical modelling approaches because of its NP-hard structure. Tabu search (TS), a mega-heuristic algorithm, plays a major role in searching for near-optimal solutions for NP-hard optimization problems. This paper develops a TS model for solving a FSS problem with the objective to reduce total weighted tardiness time, and constraint on changeover time in operations. The performance of the TS model is compared with that of traditional EDD heuristics, being used. The result shows that the objective value has been reduced by 43%, from 215.95 to 123.07 (h). It indicates that the TS model is a good approach for FSS problems.

Application of genetic algorithm, GA, to solve a flow shop scheduling problem with changeover times in operations: a case study

Phong Nguyen Nhu — 2024-06-15

Flow Shop Scheduling (FSS) Problems are examples of combinatorial optimization issues that are classified as NP-hard. Because of the NP-hard structure of FSS problems, it can be extremely challenging to find mathematical modeling methodologies that will result in an optimal solution for these problems. The Genetic Algorithm (GA), which is a metaheuristic approach, is one of the most important factors in the process of locating near-optimal answers to NP-hard optimization issues. In this research, a GA model for addressing an FSS problem was developed with the goal of lowering the overall weighted tardiness time and placing a constraint on the operation changeover time. When compared with the performance of the standard heuristics EDD, being used in the company under study, the GA model’s performance was shown to be superior. Based on the findings, it can be shown that the objective value was cut by 43%, going from 215.95 (h) to 123.07 (h). This demonstrates that the GA model is an effective strategy for addressing FSS problems.

A bimodal supply chain game model for apparel enterprises considering consumer channel preferences

Zhoulei pan — 2024-06-15

Considering the consumer’s channel preference, this paper studies the pricing strategies of clothing manufacturers and retailers mainly selling online on traditional e-commerce platforms and live e-commerce platforms, and constructs two sales modes: direct selling mode and resale mode. Based on the Stackelberg game model, the optimal pricing and profit of direct selling mode and resale mode under centralized decision-making are solved, and the variables such as imported discount, consumer trust, and demand satisfaction are analyzed in detail. The results show that a large discount can’t guarantee the maximization of platform profits and a suitable discount can effectively improve the profits of retailers and manufacturers. Traditional platform retailers effectively improve consumers’ trust in goods, which is conducive to improving their own and manufacturers’ profits; When the cost paid by consumers when purchasing goods from different channels is different, the change of consumers’ shopping cost will directly affect the pricing of goods by the two platforms.

Applying fuzzy theory to develop linguistic control charts The pLCC model

Phong Nguyen Nhu — 2024-01-12

This paper studies an approach to use fuzzy set theory and possibility theory to construct control charts – a very important on-line process control tool used in quality control. The control chart is constructed based on linguistic data. The model aims to control the process simply and effectively. The quality characteristics are modeled by fuzzy variable. The status of quality characteristics is modeled by triangle fuzzy number. Fuzzy arithmetic is used to calculate the control chart’s center line. The control chart’s control limits are constructed according to Shewhart’s principle. The fuzzy variable’s standard deviation is calculated by a model developed by Kauffman and Gupta.

Further discussion on regulations of the logistic services in Vietnam–and construction issues for logistics in Ca Mau province

Dinh Tran Ngoc Huy — 2024-03-01

Purpose: This research paper aims to present discussion on regulations of the logistic services in Vietnam and a case study of logistics in Ca Mau province. By using the panel approach, our findings: As the role of logistics has been increasingly important and China is a big export partner of our country, in Ca Mau, according to the approved plan, Nam Can Seaport is a local general port (type II), including Nam Can ports on Cai Lon river for ships up to 5,000 tons and the study "Development of seaports for ships of up to 5,000 tons". large load capacity in the Hon Khoai island area in accordance with the needs and capacity of investors.