Dynamic scheduling in a multi-product manufacturing system

To remain competitive in global marketplace, manufacturing companies need to improve their operational practices. One of the methods to increase competitiveness in manufacturing is by implementing proper scheduling system. This is important to enable job orders to be completed on time, minimize waiting time and maximize utilization of equipment and machineries. The dynamics of real manufacturing system are very complex in nature. Schedules developed based on deterministic algorithms are unable to effectively deal with uncertainties in demand and capacity. Significant differences can be found between planned schedules and actual schedule implementation. This study attempted to develop a scheduling system that is able to react quickly and reliably for accommodating changes in product demand and manufacturing capacity. A case study, 6 by 6 job shop scheduling problem was adapted with uncertainty elements added to the data sets. A simulation model was designed and implemented using ARENA simulation package to generate various job shop scheduling scenarios. Their performances were evaluated using scheduling rules, namely, first-in-first-out (FIFO), earliest due date (EDD), and shortest processing time (SPT). An artificial neural network (ANN) model was developed and trained using various scheduling scenarios generated by ARENA simulation. The experimental results suggest that the ANN scheduling model can provided moderately reliable prediction results for limited scenarios when predicting the number completed jobs, maximum flowtime, average machine utilization, and average length of queue. This study has provided better understanding on the effects of changes in demand and capacity on the job shop schedules. Areas for further study includes: (i) Fine tune the proposed ANN scheduling model (ii) Consider more variety of job shop environment (iii) Incorporate an expert system for interpretation of results. The theoretical framework proposed in this study can be used as a basis for further investigation

Sustainable Maintenance Performance Measures: A Pilot Survey in Malaysian Automotive Companies

AbstractFor sustainability to be realized the automotive companies need to cascade down their strategies to all business functions, including maintenance. Maintenance objectives at the operational level shall be aligned with business strategies at the corporate level by defining key performance measures at each level. This paper developed the initial framework for measuring sustainable maintenance performance (SMP) where 15 measures at the corporate level, 20 measures at the tactical level and 43 measures at the functional level, are identified. In sequence, this paper established the importance level of these measures through a pilot survey in Malaysian automotive companies. The findings of this study are concluded by recommending all proposed measures as important. The total of lubricants consumption has been considered as the most crucial measure at the functional level, while learning and growth is the most vital perspective, and furthermore, social factor is becoming a more important in measuring SMP

Education level, working experiences and ergonomics training effect on ergonomics awareness and practices in Malaysia

The objective of the study is to identify the effect of three demographics factors: education level, working experiences and ergonomics training on ergonomics awareness (EA) and ergonomics practices (EP). 146 questionnaires were received from Safety and Health Officers (SHOs) in Malaysian manufacturing companies. Exploratory Factor Analysis has been carried out but not discussed in this paper. Ergonomics awareness (EA) represented by four elements: knowledge in ergonomics technical (KET), beliefs on implication of work and need for improvements (BIIWNI), beliefs on the importance of assessment (BIAss) and beliefs on the importance of anthropometrics and suitability to workers (BIASW). Ergonomics practices (EP) were represented by two elements; ergonomics technical (Ergo_Tech) and ergonomics administrative (Ergo_Ad). Analysis were carried out by Levene test, MANOVA, and linear regression (stepwise). It is found that ergonomics training and working experiences as SHO have significantly interact with EA, while only ergonomic training has significantly interacted with EP. Surprisingly, education level of SHOs did not contribute significantly to both EA and EP. It is concluded that ergonomics training should be emphasized in order to get a successful ergonomics practice and it should be considered as a compulsory in order to obtain continuous program (CEP) point for renewal of SHO certificate

The moderator effects of ISO/TS16949 certification in Thailand automotive industry

In this paper, the relationship among TQM implementation, organizational performance measures and ISO/TS16949certification as moderator variable is studied. It is often claimed that ISO certification generates an improvement in the performance of organizations. This research aims to find out whether ISO/TS16949 certification indeed results in better performance outcomes for organizations in automotive industry. To test the hypothesis, an instrument is developed to measure the level of TQM implementation and organizational performance. Data were obtained from 150 Thailand automotive companies with 21% response rates and analyzed through structural equation modeling (SEM). The result indicates that ISO/TS16949 certification does not moderate the relationship between TQM implementation and organizational performance

The pedagogical issues in engineering statics

A study on students’ performance at an engineering department in a government-funded university in Malaysia revealed that the percentage of students not graduating on time and failed to graduate is high for a particular engineering program as compared to the other programs. A deeper study lead to one of the contributing factors, which is the poor students’ performance in their first year. Further investigation revealed that Statics, which students took as their first engineering course, has the highest failure rate. There are several cases where students had to repeat the course three times before obtaining a pass to be able to move on to the follow-on courses. This paper examines the pedagogical issues facing the teaching and learning of Statics in the case of this engineering department. The teaching approach of Statics and students learning difficulties in the course are discussed. This is compared with current trends and research findings in the same area worldwide. The findings in this paper would be useful for stakeholders involved in the design and development of this fundamental course

A survey report on implementation of design for assembly (DFA) in Malaysian manufacturing industries

DFA is an effective tool to reduce cost, time and improve performance and quality. DFA is widely applied in many industries and in many countries especially in the United States, United Kingdom and Japan. In Malaysia, companies will benefit extent of DFA awareness and application in Malaysian industries. This paper reports on the results of a survey carried out as part of an ongoing research at Universiti Teknologi Malaysia (UTM) on the impelmentation of DFA in Malaysia. The survey was done to determine the level of awareness and implementation of DFA in assembly-related companie

Decision support tool for job shop scheduling with job cancellation

Although most job shop scheduling problems are concerning dynamic demand and stochastic processing time, the majority of existing scheduling techniques are based on static demand and deterministic processing time. As a consequence, the solutions obtained from the traditional scheduling technique are ineffective wherever changes occur to the system. The Decision Support Tool (DST) for dynamic job shop scheduling was developed. The components of DST, namely, the knowledge-base, data-base, rule base, and graphical user interface were integrated. It provides alternative recommended schedules to be selected by practitioners with minimum knowledge in job shop scheduling. Validation of DST shows that the performance of DST is promising and able to provide comparable results as when using discrete event simulation. This paper demonstrates the capability of the DST to handling changes in demand, i.e. job cancellation. The demonstration suggests that the proposed DST can effectively handle job cancellation during early, middle or late time instances

Generation of Look-Up Tables for Dynamic Job Shop Scheduling Decision Support Tool

Majority of existing scheduling techniques are based on static demand and deterministic processing time, while most job shop scheduling problem are concerned with dynamic demand and stochastic processing time. As a consequence, the solutions obtained from the traditional scheduling technique are ineffective wherever changes occur to the system. Therefore, this research intends to develop a decision support tool (DST) based on promising artificial intelligent that is able to accommodate the dynamics that regularly occur in job shop scheduling problem. The DST was designed through three phases, i.e. (i) the look-up table generation, (ii) inverse model development and (iii) integration of DST components. This paper reports the generation of look-up tables for various scenarios as a part in development of the DST. A discrete event simulation model was used to compare the performance among SPT, EDD, FCFS, S/OPN and Slack rules; the best performances measures (mean flow time, mean tardiness and mean lateness) and the job order requirement (inter-arrival time, due dates tightness and setup time ratio) which were compiled into look-up tables. The well-known 6/6/J/Cmax Problem from Muth and Thompson (1963) was used as a case study. In the future, the performance measure of various scheduling scenarios and the job order requirement will be mapped using ANN inverse model

The learning issues in engineering statics

Rate of failure in a fundamental course in an undergraduate engineering program has been found to affect the time to graduate for many Mechanical Engineering students at a government-funded university in Malaysia. Data from the academic session 2004/2005 to 2007/2008 showed an average of 34 percent of students per semester not graduating on time. Compared to other pre-requisite and follow-on courses, students’ achievements in ‘Statics’ which students took as their first engineering course in the first year showed an average of 21 percent failures per semester for semesters 1-2004/2005 to 2-2007/2008, with the highest record of 46 percent and the lowest of 13 percent. Among these students 19 percent managed to pass after retaking the course for the third time and another 15 percent were either terminated or withdrew from the program. Based on this initial analysis, a study was conducted to examine the pedagogical issues related to the teaching and learning (T&L) of Statics. The main concerns were highlighted and will be the basis for identifying appropriate strategies for improvement. Implications from the findings would be useful to those involved in academi

Proposed relationship of TQM and organisational performance using structured equation modelling

Total quality management (TQM) has been considered as an infrastructural strategy in the operations management research field. It is one of the most recognised models for operational excellence besides lean operation, supply chain management, and technology management. Both manufacturing and service organisations tend to implement this strategy in order to maintain their competitive advantage. The purpose of this paper is to develop the conceptual model of TQM implementation in relation to organisational performance. The authors have reviewed the literature on TQM and organised the paper along two main themes: the evolution of TQM considered as a set of practices, and its impacts on organisational performance. Two research questions are proposed in order to re-validate TQM constructs: (1) Is the set of practices associated with TQM valid as a whole? (2) What performance measures should be considered to exhibit the effectiveness of its implementation