Manufacturing and Logistics
Taha Hossein Hejazi; Mirmehdi Seyyed-Esfahani; Hurieh Dezhahang; Donya Ramezani
Abstract
The challenge of designing a closed-loop supply chain (CLSC) under conditions of uncertainty and partial disruptions is complex and demanding. The concept of a closed-loop supply chain involves integrating reverse logistics into the traditional forward supply chain to establish a sustainable and environmentally ...
Read More
The challenge of designing a closed-loop supply chain (CLSC) under conditions of uncertainty and partial disruptions is complex and demanding. The concept of a closed-loop supply chain involves integrating reverse logistics into the traditional forward supply chain to establish a sustainable and environmentally friendly system. However, uncertainties and partial disruptions create significant obstacles to achieving an efficient and dependable CLSC. In order to address these challenges, the concept of chance constraint is introduced, allowing for the consideration of probabilistic uncertainties in decision-making. The goal is to develop a robust CLSC model capable of effectively managing uncertain parameters such as demand, rate of return, and product quality. The Markowitz method is utilized to address uncertainty in the objective function by combining the mean with a coefficient of standard deviation. The study's results demonstrate that incorporating uncertainty into the model leads to increased profitability compared to the deterministic model. The uncertain model is more responsive to demands and considers the dynamics of confidence inventory, leading to improved decision-making. Strategic decisions, such as the number of production, distribution, and destruction facilities, remain consistent in both models. However, the capacity of destruction centers in the uncertain model is slightly smaller due to the consideration of uncertain product quality. Furthermore, incorporating uncertainty into the model has contributed to enhancing the model's clarity and facilitating improved decision-making. This increase in profitability can be attributed to the model's heightened responsiveness to demands, as well as its dynamic approach to managing confidence inventory.
Manufacturing and Logistics
Robert S. Keyser; Renee S. Severin; Matthew J. Geiger
Abstract
The Single-Minute Exchange of Dies (SMED) methodology proved to be an effective approach for reducing setup times on a bottleneck 66” Koppers rotary die-cutter machine center in a corrugated box plant. Root cause analysis techniques, such as a check sheet and control charts, aided the analysis. ...
Read More
The Single-Minute Exchange of Dies (SMED) methodology proved to be an effective approach for reducing setup times on a bottleneck 66” Koppers rotary die-cutter machine center in a corrugated box plant. Root cause analysis techniques, such as a check sheet and control charts, aided the analysis. The supervisor and work crew, consisting of both the operator and setup person, played an integral role in reducing setup times by consenting to being videotaped during a typical setup and then breaking down the video to distinguish internal versus external steps. By converting many internal steps to external steps, average setup times were reduced from 55 minutes to 32 minutes, a 42% improvement.
Manufacturing and Logistics
Sania Heidari; Sajjad Shoukohyar; Davoud Mohammaditabar; Vahidreza Ghezavati
Abstract
The purpose of this paper is to identify and classify the main factors implementing the Cloud Manufacturing Systems (CMS) in the internet service providers company by Fuzzy Cognitive Map (FCM) methodology. Through expert opinions, 20 main factors were identified and classified based on the importance ...
Read More
The purpose of this paper is to identify and classify the main factors implementing the Cloud Manufacturing Systems (CMS) in the internet service providers company by Fuzzy Cognitive Map (FCM) methodology. Through expert opinions, 20 main factors were identified and classified based on the importance and then a FCM approach was applied for obtaining the relationship between the factors, and all of the impact factors are outputs of expert opinion. The outcomes of the study highlighted those three factors, including customer scoring, R&D, and method development were the most important factors impressing the implementation CMSs. Present practices for implementation CMS are and the relationship between the main factors also impressing CMS by employing the FCM approach in the Iranian internet service provider company. The model obtained in this study guides the managers to identify and classify the important factors of the cloud manufacturing and finally implement it successfully.
Manufacturing and Logistics
Robert S Keyser
Abstract
Root cause analysis techniques are often applied to problems in the workplace; however, they may also prove very useful when applied to home projects. This research explores the application of root cause analysis techniques in three home projects: (1) Cause-and-Effect diagram to remove Palmetto bugs ...
Read More
Root cause analysis techniques are often applied to problems in the workplace; however, they may also prove very useful when applied to home projects. This research explores the application of root cause analysis techniques in three home projects: (1) Cause-and-Effect diagram to remove Palmetto bugs in a condo dwelling, (2) Five Whys method to repair a sunroof water leak in a car, and (3) Fault Tree Analysis to repair a Toro string trimmer that starts, then dies. The effective use of root cause analysis techniques can have a meaningful impact on resolving home project issues resulting in a restoration of homeowner issues as well as reduced homeowner anxiety, repair time, and repair cost.
Manufacturing and Logistics
Aurpon Tahsin Shams; Kamrul Hasan
Abstract
A bottleneck machine in a production line will reduce the productivity of the whole. The results of having a bottleneck are stalls in production, supply overstock, pressure from customers, and low employee morale. This paper focuses on the identification of the bottleneck in the production process of ...
Read More
A bottleneck machine in a production line will reduce the productivity of the whole. The results of having a bottleneck are stalls in production, supply overstock, pressure from customers, and low employee morale. This paper focuses on the identification of the bottleneck in the production process of “Bangladesh cable silpa limited” and after the identification, tries to mitigate the bottleneck. A bottleneck machine or process causes starving or blocking of parts in the system, thus, therefore, increases the non-value added time and reduces the system performance. In this work, the bottleneck process is identified by using ARENA simulation based on the highest utilization rate and longest queue length matrices. Then, the bottleneck is reduced by increasing the capacity or the number of the machine in the bottleneck process. We can see the effect of changing the capacity of the process without changing the actual production line. Calculating it in a conventional way is very time consuming too. The last step of the thesis is to do an economic analysis. Because when the capacity of the process is increased, the production rate increases but the additional capacity increases the cost of the production.
Manufacturing and Logistics
Taposh Kumar Kapuria; Mustafizur Rahman; Shuvo Haldar
Abstract
Garments industry is playing the pioneering role in improving Bangladesh economic condition. It was started in late 1970’s and now the leading foreign currency earner for Bangladesh. It’s no dubiousness to say that, the Bangladesh garment industry is ameliorating garment’s service quality ...
Read More
Garments industry is playing the pioneering role in improving Bangladesh economic condition. It was started in late 1970’s and now the leading foreign currency earner for Bangladesh. It’s no dubiousness to say that, the Bangladesh garment industry is ameliorating garment’s service quality and innovative design features to exist in the global competitive market. Global competition in the garment’s market is changing day to day. Leading garment manufacturer from all over the world are adopting new innovative features and techniques to sustain global fierce competitive market. But the point is, Bangladeshi garment manufacturers are not lingered. They are also emphasizing on better service quality by adding latest design features and using the latest technologies to the garments. The sole purpose of this paper is to identify the root causes of sewing defects of an apparel industry in Bangladesh and continuous improvement in reducing the defects through Kaizen (Continuous Improvement) system. In short, productivity improvement of the apparel industry. Our studied garment manufacturing company is “ABONTI Color Tex. Ltd.”. Pareto Analysis is used to identify the top defect items. Cause-Effect Analysis helped to identify the root causes of sewing defects. Then, Kaizen is used for continuous improvement of the minimization of sewing defects.
Decision analysis and methods
Mahmoud. A. Barghash; Nabeel Al-Mandahawi; N. AbuJbara; R. Al-Abbadi; S. Hussein
Abstract
Cellular manufacturing is an important tool for manufacturing firms which leads to better productivity, focused and specialized manufacturing process. To utilize this important tool, the machines have to be grouped into cells. This work is related to using cellular manufacturing in a pharmaceutical factory ...
Read More
Cellular manufacturing is an important tool for manufacturing firms which leads to better productivity, focused and specialized manufacturing process. To utilize this important tool, the machines have to be grouped into cells. This work is related to using cellular manufacturing in a pharmaceutical factory with alternative routing. This adds more choices in the decision making process and presses for a better tool to make optimal selection. Several objectives may be considered to improve the productivity objectives such as the total number of exits and planning and scheduling robustness related objectives like bottleneck utilization and load balance between and within the alternative routes. Analytical hierarchical process (AHP) is used as a multi-objective decision making process to evaluate the best scenario amongst generated using simulation as a tool for modeling and evaluating the output for each scenario. Three customer case studies were considered with different preferences and the AHP evaluated the best scenario to fit these preferences. The best scenario can vary from one customer preferences to another but for the current system it turned out to be the same choice.
