Applied Mechanics and Materials Vols. 465-466

Abstract: The problem illustrated in this paper resembles a four machine permutation re-entrant flow shop with the process routing of M1,M2,M3,M4,M3,M4 where M1 and M4 have high tendency of being the dominant machines. Due to the re-entrant and permutation nature of the process routing, the actual bottlenecks were identified as M1 and combinations of M4+M3+M4. A constructive bottleneck-based heuristic known as C-ABAM was developed to minimise the makespan of the four machine permutation re-entrant flow shop using bottleneck analysis. The results showed that C-ABAM produces better result than the original ABAM heuristic introduced by Bareduan and Hasan in 2009. It was shown that at any P1 dominance level value, the C-ABAM heuristic was capable to produce near optimal results for the 6 jobs problem sizes studied. The C-ABAM heuristic was also capable to generate results which are very compatible to the NEH. To some extent, within 6 jobs problems simulation conducted during the study, the C-ABAM shows marginally better makespan performance compared to the NEH at strong dominance level.

Abstract: The Single Minute Exchange of Die (SMED), a process-based innovation originally published in the mid-1980s, involves the separation and conversion of internal setup operations into external ones. Traditionally some of the manufacturing company facing the problem loss of available time due to spent time for the changeover processes. Changeover process time meaning changing the programming or operation sequences on the machine based on process requirement during the change from one to another one model especially for the mixing parts. SMED technique is a systematic approach that enables to reduce dramatically the set-up time or changeover time. Normally in the SMED technique, it was segregated between internal and external set-up. External set-up means any processing time was done up front which is before machine stop and internal time is any tasks was performed during machine in operating, which is considering changeover time. The impact to organization that it was increasing the productivity, capacity and at the same time increased the revenue. This paper focuses on the improving the productivity on the CNC machine process through implementing SMED technique and eliminating waste in the case study company.

Abstract: Automated recognition of process variation patterns using an artificial neural network (ANN) model classifier is a useful technique for multivariate quality control. Proper design of the classifier is critical for achieving effective recognition performance (RP). The existing classifiers were mainly designed empirically. In this research, full factorial design of experiment was utilized for investigating the effect of four design parameters, i.e., recognition window size, training data amount, training data quality and hidden neuron amount. The pattern recognition study focuses on bivariate correlated process mean shifts for cross correlation function, ρ = 0.1 ~ 0.9 and mean shifts, μ = ± 0.75 ~ 3.00 standard deviations. Raw data was used as input representation for a generalized model ANN classifier. The findings suggested that: (i) the best performance for each pattern could be achieved by setting different design parameters through specific classifiers, which (ii) gave superior result (average RP = 98.85%) compared to an empirical design (average RP = 96.5%). This research has provided a new perspective in designing ANN pattern recognition scheme in the field of statistical process control.

Abstract: This paper identifies the trends in existing literatures on management system standards such as Quality (Q), Environmental (E), Occupational Health and Safety (OHS), and Energy (En) Management System (MS). Literatures related to these management system standards (MSSs) and its integrations published between year 1980 to 2012 have been critically analyzed. It provides a general overview of the Integrated Management System (IMS) implementation and the composition of MSSs in developing IMS in various organizations. Based on the analysis, it is firm that the integration of these four (4) MSSs has not been well established. Despite that, the recurring themes of the literatures related to IMS are mainly, model for implementation, strategies and guidelines for implementation, benefits of implementation, barriers/ problems of implementation, audit of IMS, Critical Success Factors for implementing IMS and IMS Audits.

Abstract: In Malaysia, Liquefied Petroleum Gas (LPG) is filled in a heavy steel cylinder and it is widely used for cooking purpose. Due to its dimensions and mass, the delivery men exposed to ergonomics risk factors associated with excessive force that can lead to injury to the back and the shoulders. There are assistive devices can be used to aid the delivery men; however, those devices are not efficient to transport the LPG cylinder to non-elevator apartments. Based on this reason, this study develops a questionnaire to determine design requirements of the assistive device for LPG cylinder handling. Structured interview using questionnaire survey was conducted among 25 delivery men. Based on the questionnaire survey, 76% of the delivery men required an assistive device that is safe, motorized, and push oriented for LPG cylinder handling. This study concluded that the developed questionnaire is reliable to determine design requirements of the assistive device for LPG cylinder handling.

Abstract: Hands are important tools for manual work. Although researchers have identified factors that influence the grip efforts of an entire hand, there appears to be limited research concerning the use of different pinch techniques and how they affect the performance of pinch effort. Therefore, the aim for this pilot study is to determine the effects of different pinch techniques on pinch effort. A total of 110 manual workers from a wooden pallet manufacturing firm participated in this study, which involved an experiment and survey to investigate the most preferred pinch technique applied on screw knobs. The techniques used were the 3-jaw chuck, pulp-2 and lateral pinch. A total of 6 screw knobs of different shapes and sizes were used. After the data were collected, descriptive and Cronbach's alpha reliability analyses were carried out. The results show that the preferred pinch technique for the small cylindrical knob, small sphere knob and all large knobs is the lateral pinch. However, the 3-jaw chuck pinch is preferred for the small 5-lobes knob. This study provides preliminary information for further research on pinch techniques and their influences on the pinching outcomes of individuals.

Abstract: Hand and finger-related injuries are increasingly common in the manufacturing industry. In relation to this, researchers have conducted various studies and found that a clockwise torque can produce a greater grip force than a counterclockwise torque direction, hence improving the grip control and exertion of an individual. However, there appears to be limited studies that explore this theory in the circumstances of pinch grips. Thus, the aim of this study is to explore the effects of different torque directions on the pinch grips. 6 prototype industrial screw knobs were designed, produced and evaluated by surveying 160 workers from a manufacturing firm. The results show that although the sizes are different, the effort to turn the knobs with a counterclockwise torque direction is still greater than the effort with a clockwise torque direction, which can technically mean that the pinch exertion in a clockwise torque direction is relatively greater. Based on these findings, guidelines can be developed to further improve hand tool designs and the capacity of torque exertions to potentially increase human performance and the effectiveness in tasks at the workplace.

Abstract: Failure in proper design of ergonomic hand tools can lead to the prevalence of hand-related injuries. In order to improve the ergonomics of hand tools, numerous studies have been done on causal factors related to these injuries such as grip postures, grip forces and torque directions. Nevertheless, there appears to be limited studies concerning how pinch effort can change with different types of tactile sensations. Therefore this study aims to determine the effects of different tactile sensations on pinch effort. A total of 110 manual workers from the wooden pallets and furniture manufacturing firm participated in the study. The descriptive analyses were conducted in Microsoft Excel 2010 and the reliability of data was verified using Cronbach's alpha reliability analyses. The results show that individuals can produce a greater pinch effort while gripping objects that have a high friction coefficient between the fingers and the grip surface. This study improves our understanding on the implications of different tactile sensations and potentially decreases workplace hazards for eventual improvements on safety, health and medical costs.

Abstract: Lean manufacturing is one of the initiatives that many major businesses in the world have been trying to adopt in order to remain competitive in an increasingly global market. The focus of the approach is on cost reduction by eliminating non-value added activities. Originating from the Toyota Production System, many of the tools and techniques of lean manufacturing have been widely used in discrete manufacturing. The purpose of this study is to investigate the approach of adopting lean, the tools and techniques implemented, the changes in the organizations, the problems encountered as well as the lessons learnt. This paper describes the results and findings of four industrial case studies conducted in different electrical and electronics companies in Malaysia. Interviews were conducted with the key personnel to answer some issues which were crucial in this study. Comparisons and discussion were made among the case companies. One of the key findings obtained is that people in the organization should take the lean mind-set and act in the lean way in order to make a lean initiative successful. The application of kaizen and 7 quality control tools are most popular implementation in the selected case study companies as the tools to eliminate non-value added activities.

Abstract: The exponentially weighted moving average (EWMA) control charts are widely used for detecting process shifts of small and moderate sizes in Statistical Process Control (SPC).This article presents an algorithm for the optimization design of a multi-EWMA scheme comprising two EWMA control charts (known as 2-EWMA chart) considering random process shifts in mean. The random process shifts in mean is characterized by a Rayleigh distribution. The design algorithm optimizes the charting parameters of the 2-EWMA chart based on loss function. Comparative study shows that the optimal 2-EWMA chart outperforms the original 2-EWMA chart, as well as the original EWMA chart. In general, this article will help to enhance the detection effectiveness of the 2-EWMA chart, and facilitate its applications in SPC.