Modelling and Optimization of Energy Efficient Assembly Line Balancing Using Modified Moth Flame Optimizer

Energy utilization is a global issue due to the reduction of fossil resources and also negative environmental effect. The assembly process in the manufacturing sector needs to move to a new dimension by taking into account energy utilization when designing the assembly line. Recently, researchers studied assembly line balancing (ALB) by considering energy utilization. However, the current works were limited to robotic assembly line problem. This work has proposed a model of energy efficient ALB (EE-ALB) and optimize the problem using a new modified moth flame optimizer (MMFO). The MMFO introduces the best flame concept to guide the global search direction. The proposed MMFO is tested by using 34 cases from benchmark problems. The numerical experiment results showed that the proposed MMFO, in general, is able to optimize the EE-ALB problem better compared to five comparison algorithms within reasonable computational time.  Statistical test indicated that the MMFO has a significant performance in 75% of the cases. The proposed model can be a guideline for manufacturer to set up a green assembly line in future

Introduction of AHP Decision Model for Prioritizing Critical Risk of WMSD in the Automotive Working Environment

Work-related musculoskeletal disorders (WMSD) is one of the essential occupational diseases that is a frequent and prevalent pain complaint by automotive workers. The importance of decisions in WMSD risk factors is related to the type of job task and working environment. This paper introduces the AHP decision model as an ergonomics assessment tool to determine relative measures of significance and assess priority weights for different risk categories of WMSD. This paper broadly categorizes the identified risk factors for WMSD into individual, organizational, physical, and psychosocial factors. Organizational factors indicated the most critical ergonomics risk factors influencing WMSD growth among automotive component manufacturer workers. Meanwhile, exposure to physical demand at work (EPD) and high workload (HWL) are the most critical risk factors. Since the various risk factors occurring under each category may vary significantly from context to context, a practical method for assessing and determining some significance level is required. AHP analysis does this in WMSD risk factors in the automotive working environment and is used as an ergonomics assessment tool

Development of a discrete event simulation tool for assembly line simulation

Discrete event simulation (DES) is a powerful tool for better decision-making. Its application can be found in almost every sector ranging from industrial to services. However, the cost of commercial DES tools sometimes makes them unaffordable for small and medium enterprises. On the other hand, the open-source DES requires good programming knowledge for model customization. This paper presents the development of the DES tool specifically for production and assembly line simulation. The developed tool known as Discrete Event Simulation for Assembly Line (DESIMAL) is flexible enough to support different types of the assembly line. Testing and validation have been conducted using an industrial case study. The result indicated that the developed DESIMAL has similar output with a small error margin (1.08% – 3.60%) compared with commercial DES software. In comparison with real problem output, DESIMAL obtained the result with an error of less than 5%. Therefore, the developed DESIMAL has been validated as an acceptable tool for assembly line simulation. The main contribution of this work is an establishment of DES tool for assembly line simulation

Multi-objective multi-verse optimiser for integrated two-sided assembly sequence planning and line balancing

Research in assembly optimisation is presently inclined towards integrative measures. Several benefits of simultaneously optimised Assembly Sequence Planning (ASP) and Assembly Line Balancing (ALB) have been highlighted by researchers to have better solution quality, shorter time-to-market, and minimalised error during planning. Recently, several efforts have been made to realise integrated assembly optimisation. However, none of the published research considered the two-sided assembly line problem. This paper presents an integrated ASP and ALB optimisation in a two-sided assembly environment (2S-ASPLB), which is mainly adopted in automotive assembly process. In this study, the 2S-ASPLB problem was formulated and optimised using Multi-Objective Multi-Verse Optimiser (MOMVO) by considering line efficiency, reorientation penalty, and tool change as the optimisation objectives. The computational experiments were conducted in a few stages, beginning with the identification of the best decoding approach for 2S-ASPLB. Next, the best MOMVO coefficient was studied, followed by comparing MOMVO performance with well-established multi-objective optimisation algorithms. Finally, a case study problem was presented to demonstrate applicability of the proposed model and algorithm in real-life problem. The results indicated that the priority factor (PF) decoding approach had better performance compared with others. Meanwhile, in comparison with well-established algorithms, MOMVO performed better in convergence and solution distribution. The case study results indicated the applicability of proposed 2S-ASPLB model and algorithm to improve line efficiency in assembly line. The main contribution of the research is a new 2S-ASPLB model and optimisation scheme, which can assist manufacturer in designing better assembly layout

A hybrid knowledge-based system for collaborative green manufacturing management

This research is oriented towards the development of a new hybrid knowledge-based system for planning, design, and implementation of collaborative green manufacturing system (CGMM). We propose the development of a conceptual model of CGMM, and then translate it into a knowledge-based system, with the goal of investigating the recent state of green manufacturing philosophy practised in the automotive industry and its supply chain as compared to the ideal system. A prototype of reliable hybrid KBS is produced as a decision making tool to assist the management and policy makers in implementing the CGMM.The system captured the activities in the CGMM that have potential opportunity for collaborative development through the green value chain gap measurement in CGMM The results showed what the organizations‟ potential opportunity of their abilities compared to their partners‟ potential opportunity in the green supply chai

Modelling and optimization of energy efficient assemblyline balancing using modified moth flame optimizer

Energy utilization is a global issue due to the reduction of fossil resources and also negative environmental effect. The assembly process in the manufacturing sector needs to move to a new dimension by taking into account energy utilization when designing the assembly line. Recently, researchers studied assembly line balancing (ALB) by considering energy utilization. However, the current works were limited to robotic assembly line problem. This work has proposed a model of energy efficient ALB (EE-ALB) and optimize the problem using a new modified moth flame optimizer (MMFO). The MMFO introduces the best flame concept to guide the global search direction. The proposed MMFO is tested by using 34 cases from benchmark problems. The numerical experiment results showed that the proposed MMFO, in general, is able to optimize the EE-ALB problem better compared to five comparison algorithms within reasonable computational time. Statistical test indicated that the MMFO has a significant performance in 75% of the cases. The proposed model can be a guideline for manufacturer to set up a green assembly line in future

Ergonomic embedded in designing welding assembly tool for automotive manufacturing process

Ergonomics focuses on understanding how workers interact with their work environment, tools, and equipment. The proper ergonomics consideration in tool design will impact worker safety and productivity. Ergonomics-embedded knowledge is critical in designing welding assembly tools for automotive manufacturing. The study aims to improve the ergonomic issues faced by the automotive assembly welders. The methodology involves studying the existing welding assembly process in automotive manufacturing regarding RULA scores and simulating the postures using CATIA analysis. Based on the simulation, critical ergonomics issues should be identified and analyzed. Finally, the welding process is improved by designing the hand support for the workers to assemble parts. The results revealed that the RULA scores have improved from 7 (high risk at the existing condition) to 3 (medium risk) for both worker's hands after the support of the assembly tool. In conclusion, ergonomic embedding in welding assembly tool design has improved the automotive assembly worker's well-being. The findings of this study contribute to the growing body of knowledge on integrating ergonomics into automotive manufacturing processes, providing valuable insights for industry practitioners and researchers alike

Ergonomics study in Quick Response Manufacturing (QRM) automotive workstation environment to overcome employee complaints

The assembly line is an important process in producing a complete car unit before the product is checked and delivered to the consumer. Assembly workers during working hours are affected by work position, workload, placement of components and aids during the process and equipment used in assisting heavy work processes. Work positions with non-ergonomic workloads impact the disability and musculoskeletal complaints (MSD) of workers. The purpose of this study is to identify the ergonomic risks of assembly workers. Analytical methods using the Nordic Body Map (NBM) and QRM principles were used in this study. The results of the analysis of the level of complaints of workers’ MSD during the work were obtained for the categories of not sick (NS) 27.94%, slightly sick (SS) 36.76%, sick (S) 29.69% and very sick (VS) 5.6%. The most dominant complaints about S and VS complaints were shoulders, arms, back, waist, buttocks, wrists and hands. MSD complaints that employees feel are in the middle category with an average score of 64 points which means immediate remedial action is needed. Using the time-focused QRM principle, improvements in work procedures and designing ergonomic tools are needed to minimize MSD complaints that impact working hours faster, and there is no overtim

The implementation of lean manufacturing and ergonomics in small medium enterprise – Case study

Productivity can be increased by eliminating of all wastes. The objective of lean manufacturing is to eliminate wastes. Commonly, there are seven wastes known as transport, inventory, motion, waiting, over processing, overproduction and defects. However, ergonomics is a process to improve the working posture by designing or arranging a workplace, system and material handling. The aim of this study is to improve the productivity through the integration of basic lean manufacturing and ergonomics in the food company. The walkthrough and distribution of questionnaire have been conducted in this company. Each activity was observed to identify non-value-added activity and work related muscular skeletal disorder (WMSD) that affect the productivity by using questionnaire, motion study and Rapid Upper Limb Assessment (RULA). The questionnaire result has shown that the most of wasted motion is in weighing and measuring activity. In addition, all workers in this process were affected by the musculoskeletal disorder at their neck and shoulder. All movement were simulated through Delmia software. The RULA score shows that the worker had experienced pain at the arm and wrist. The score also suggested that the process should be changed immediately. The changes might reduce the worker's pain and increase the productivity

The antimetastatic and antiangiogenesis effects of kefir water on murine breast cancer cells

Background. Kefir is a unique cultured product that contains beneficial probiotics. Kefir culture from other parts of the world exhibits numerous beneficial qualities such as anti-inflammatory, immunomodulation, and anticancer effects. Nevertheless, kefir cultures from different parts of the world exert different effects because of variation in culture conditions and media. Breast cancer is the leading cancer in women, and metastasis is the major cause of death associated with breast cancer. The antimetastatic and antiangiogenic effects of kefir water made from kefir grains cultured in Malaysia were studied in 4T1 breast cancer cells. Methods. 4T1 cancer cells were treated with kefir water in vitro to assess its antimigration and anti-invasion effects. BALB/c mice were injected with 4T1 cancer cells and treated orally with kefir water for 28 days. Results. Kefir water was cytotoxic toward 4T1 cells at IC50 (half-maximal inhibitory concentration) of 12.5 and 8.33 mg/mL for 48 and 72 hours, respectively. A significant reduction in tumor size and weight (0.9132 ± 0.219 g) and a substantial increase in helper T cells (5-fold) and cytotoxic T cells (7-fold) were observed in the kefir water–treated group. Proinflammatory and proangiogenic markers were significantly reduced in the kefir water–treated group. Conclusions. Kefir water inhibited tumor proliferation in vitro and in vivo mainly through cancer cell apoptosis, immunomodulation by stimulating T helper cells and cytotoxic T cells, and anti-inflammatory, antimetastatic, and antiangiogenesis effects. This study brought out the potential of the probiotic beverage kefir water in cancer treatment