International Journal of Manufacturing Technology and Management http://www.inderscience.com/browse/index.php?journalID=21&year=2011&vol=23&issue=1/2 Inderscience Publishers Ltd en-uk International Journal of Manufacturing Technology and Management 1368-2148 1741-5195 © 2011 Inderscience Publishers Ltd editor@inderscience.com https://www.inderscience.com/images/files/coverImgs/ijmtm_scoverijmtm.jpg http://www.inderscience.com/browse/index.php?journalID=21&year=2011&vol=23&issue=1/2 http://www.inderscience.com/link.php?id=42105 Unbalanced production systems often operate in the regimes, where the departments with lower throughput operate overtime to prevent starvation of those with higher throughput. The work-in-process, built-up during the overtime, is referred to as the 'float.' In this paper, we study such a system consisting of two departments obeying the Bernoulli reliability model. Specifically, we provide a method for performance analysis and offer a technique to calculate the smallest, i.e., lean, float capacity necessary and sufficient to obtain the system throughput equal to that of the best department. Four design approaches are considered, and it is shown that the ones based on transient analysis ensure superior performances. Unbalanced production systems with floats: analysis and lean design
Semyon M. Meerkov, Liang Zhang
International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 4 - 15
Unbalanced production systems often operate in the regimes, where the departments with lower throughput operate overtime to prevent starvation of those with higher throughput. The work-in-process, built-up during the overtime, is referred to as the 'float.' In this paper, we study such a system consisting of two departments obeying the Bernoulli reliability model. Specifically, we provide a method for performance analysis and offer a technique to calculate the smallest, i.e., lean, float capacity necessary and sufficient to obtain the system throughput equal to that of the best department. Four design approaches are considered, and it is shown that the ones based on transient analysis ensure superior performances.

]]> 10.1504/IJMTM.2011.042105 International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 4 - 15 Semyon M. Meerkov Liang Zhang Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109 2122 USA. ' Department of Industrial and Manufacturing Engineering, University of Wisconsin-Milwaukee, Milwaukee, WI 53201 USA unbalanced production systems float-based systems Bernoulli machines transient analysis work-in-process WIP reliability modelling floats lean design. 2011-08-26T23:20:50-05:00 23 1/2 4 15 2011-08-26T23:20:50-05:00 http://www.inderscience.com/link.php?id=42106 Pull production control systems are usually implemented by means of Kanban cards. Kanban cards can be established either statically (card setting) or dynamically (card controlling). As card controlling seems to have a number of advantages over card setting, several card controlling mechanisms (CCM) have been proposed in the literature. The CCM automatically adjust the number of cards required depending on the status of the system and on the values of certain constants or parameters. Therefore, the performance of a CCM is greatly affected by the correct setting of its parameters. In this paper, we address the parameter setting in a specific CCM designed for Conwip systems. We focus on this mechanism as it has proved to outperform other CCM for a variety of scenarios. We suggest a methodology based on response surface methodology (RSM) statistical procedure for parameter setting. In order to test its suitability, we apply this methodology to a five-station line. The results show that the performance of the CCM for the predicted values of parameters is very close to the optimal solution, obtaining savings of 82% in the number of simulations, as compared to the results obtained by an exhaustive search of all possible parameter combinations. A response surface methodology for parameter setting in a dynamic Conwip production control system
Pedro L. Gonzalez-R, Jose M. Framinan, Rafael Ruiz-Usano
International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 16 - 33
Pull production control systems are usually implemented by means of Kanban cards. Kanban cards can be established either statically (card setting) or dynamically (card controlling). As card controlling seems to have a number of advantages over card setting, several card controlling mechanisms (CCM) have been proposed in the literature. The CCM automatically adjust the number of cards required depending on the status of the system and on the values of certain constants or parameters. Therefore, the performance of a CCM is greatly affected by the correct setting of its parameters. In this paper, we address the parameter setting in a specific CCM designed for Conwip systems. We focus on this mechanism as it has proved to outperform other CCM for a variety of scenarios. We suggest a methodology based on response surface methodology (RSM) statistical procedure for parameter setting. In order to test its suitability, we apply this methodology to a five-station line. The results show that the performance of the CCM for the predicted values of parameters is very close to the optimal solution, obtaining savings of 82% in the number of simulations, as compared to the results obtained by an exhaustive search of all possible parameter combinations.

]]> 10.1504/IJMTM.2011.042106 International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 16 - 33 Pedro L. Gonzalez-R Jose M. Framinan Rafael Ruiz-Usano Industrial Management, School of Engineering, University of Seville, Camino de los Descubrimientos, s/n, 41092 Sevilla, Spain. ' Industrial Management, School of Engineering, University of Seville, Camino de los Descubrimientos, s/n, 41092 Sevilla, Spain. ' Industrial Management, School of Engineering, University of Seville, Camino de los Descubrimientos, s/n, 41092 Sevilla, Spain production control Conwip card controlling mechanisms response surface metodology RSM pull systems kanban parameter setting. 2011-08-26T23:20:50-05:00 23 1/2 16 33 2011-08-26T23:20:50-05:00 http://www.inderscience.com/link.php?id=42107 Labour turnover is one of the major complications that industry faces on a daily basis. Turnover is particularly harmful to serial assembly lines. The learning process that a new operator must undergo when first introduced to an assembly line station generates blockage and starvation in the previous and successive stations, causing a reduction in the line's throughput. In this paper, we analyse different work allocation strategies for serial assembly line designs in order to determine which designs perform best under the presence of labour turnover and a task-learning process. In particular, we compare the traditional balanced line with two other assembly line designs, a variant of the bucket brigades (BB) and a hybrid method – the modified work sharing (MWS) method. By making a judicious use of control buffers, the MWS method seeks to combine the positive characteristics of both the BB and traditional balanced lines to naturally adapt to different levels of labour turnover. The results presented in this paper show that the MWS outperforms the BB and the balanced designs. The use of dynamic work sharing production methods to reduce the impact of labour turnover in serial assembly lines
J. Rene Villalobos, Marco A. Gutierrez, Luis R. Mar, Octavio Sanchez, Omar Ahumada
International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 34 - 53
Labour turnover is one of the major complications that industry faces on a daily basis. Turnover is particularly harmful to serial assembly lines. The learning process that a new operator must undergo when first introduced to an assembly line station generates blockage and starvation in the previous and successive stations, causing a reduction in the line's throughput. In this paper, we analyse different work allocation strategies for serial assembly line designs in order to determine which designs perform best under the presence of labour turnover and a task-learning process. In particular, we compare the traditional balanced line with two other assembly line designs, a variant of the bucket brigades (BB) and a hybrid method – the modified work sharing (MWS) method. By making a judicious use of control buffers, the MWS method seeks to combine the positive characteristics of both the BB and traditional balanced lines to naturally adapt to different levels of labour turnover. The results presented in this paper show that the MWS outperforms the BB and the balanced designs.

]]> 10.1504/IJMTM.2011.042107 International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 34 - 53 J. Rene Villalobos Marco A. Gutierrez Luis R. Mar Octavio Sanchez Omar Ahumada International Logistics and Productivity Improvement Laboratory, Fulton School of Engineering, Arizona State University, P.O. Box 878809, Tempe, AZ 85287-8809, USA. ' International Logistics and Productivity Improvement Laboratory, Fulton School of Engineering, Arizona State University, P.O. Box 878809, Tempe, AZ 85287-8809, USA. ' International Logistics and Productivity Improvement Laboratory, Fulton School of Engineering, Arizona State University, P.O. Box 878809, Tempe, AZ 85287-8809, USA. ' International Logistics and Productivity Improvement Laboratory, Fulton School of Engineering, Arizona State University, P.O. Box 878809, Tempe, AZ 85287-8809, USA. ' International Logistics and Productivity Improvement Laboratory, Fulton School of Engineering, Arizona State University, P.O. Box 878809, Tempe, AZ 85287-8809, USA labour turnover dynamic work allocation DWA work sharing serial assembly lines bucket brigades control buffers balanced assembly lines. 2011-08-26T23:20:50-05:00 23 1/2 34 53 2011-08-26T23:20:50-05:00 http://www.inderscience.com/link.php?id=42108 The performance of unpaced production lines that are unbalanced in terms of both their operation time means and buffer storage sizes is studied in this paper. The lines were simulated under their steady-state operational mode of operation with various values of line length, buffer storage capacity, degree of imbalance, and patterns of imbalance. Output data (principally idle time and average buffer level) were analysed utilising a number of statistical tools. In terms of idle time, it was found that the best unbalanced pattern is an MT bowl configuration, coupled with a distribution of buffer capacity as evenly as possible. With respect to ABL, the best pattern turned out to be a monotone decreasing MT order, together with an ascending buffer size order. Unpaced production lines with jointly unbalanced operation time means and buffer capacities – their behaviour and performance
Sabry Shaaban
International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 54 - 68
The performance of unpaced production lines that are unbalanced in terms of both their operation time means and buffer storage sizes is studied in this paper. The lines were simulated under their steady-state operational mode of operation with various values of line length, buffer storage capacity, degree of imbalance, and patterns of imbalance. Output data (principally idle time and average buffer level) were analysed utilising a number of statistical tools. In terms of idle time, it was found that the best unbalanced pattern is an MT bowl configuration, coupled with a distribution of buffer capacity as evenly as possible. With respect to ABL, the best pattern turned out to be a monotone decreasing MT order, together with an ascending buffer size order.

]]> 10.1504/IJMTM.2011.042108 International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 54 - 68 Sabry Shaaban Department of Finance, ESC La Rochelle, 102 Rue de Coureilles, 17024 La Rochelle, France unpaced production lines simulation unequal service time means uneven buffer capacities imbalance patterns unbalanced operation time means buffer storage size line length idle time average buffer level. 2011-08-26T23:20:50-05:00 23 1/2 54 68 2011-08-26T23:20:50-05:00 http://www.inderscience.com/link.php?id=42109 Production lines are widely used in high volume industries and vary in their sophistication from simple to the complicated structured such as parallel, reworks, feed-forward, etc. One of the common production styles in many modern industries is the parallel production system with rework path (PPS-RP) and one of the methods used for studying the PPS-RP design is through genetic algorithm (GA). As a one of the important tasks in using GA is how to express a chromosome. This paper attempts to find the nearest optimal design of a PPS-RP that will maximise production efficiency by optimising the following two decision variables: buffer size between each pair of work stations and machine numbers in each of the work stations. In order to do this, a new GA-simulation based method to find the nearest optimal design for the proposed PPS-RP is introduced. For efficient use of GA, the used GA methodology is based on a technique that is called non-homogeneous gene arrangement method (NGAM) which arranges the genes inside individuals. An experimental numerical examples showed that after a number of operations based on the proposed simulator, it was possible to get the nearest optimal design of PPS-RP. Modelling of parallel production system with rework paths and its GA based simulator for optimal design
Khalid R. Al-Momani, Jaber E. Abu Qudeiri
International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 69 - 81
Production lines are widely used in high volume industries and vary in their sophistication from simple to the complicated structured such as parallel, reworks, feed-forward, etc. One of the common production styles in many modern industries is the parallel production system with rework path (PPS-RP) and one of the methods used for studying the PPS-RP design is through genetic algorithm (GA). As a one of the important tasks in using GA is how to express a chromosome. This paper attempts to find the nearest optimal design of a PPS-RP that will maximise production efficiency by optimising the following two decision variables: buffer size between each pair of work stations and machine numbers in each of the work stations. In order to do this, a new GA-simulation based method to find the nearest optimal design for the proposed PPS-RP is introduced. For efficient use of GA, the used GA methodology is based on a technique that is called non-homogeneous gene arrangement method (NGAM) which arranges the genes inside individuals. An experimental numerical examples showed that after a number of operations based on the proposed simulator, it was possible to get the nearest optimal design of PPS-RP.

]]> 10.1504/IJMTM.2011.042109 International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 69 - 81 Khalid R. Al-Momani Jaber E. Abu Qudeiri Industrial Engineering Department, Jordan University of Science and Technology, P. O. Box 3030, Irbid 22110, Jordan. ' Mechatronics Engineering Department, Philadelphia University, P.O. Box 1, Amman 19392, Jordan parallel production systems PPS production system design buffer size rework paths genetic algorithms GAs optimal design production efficiency. 2011-08-26T23:20:50-05:00 23 1/2 69 81 2011-08-26T23:20:50-05:00 http://www.inderscience.com/link.php?id=42110 Disassembly lines are inherently multicriteria, with balance having the possibility of being one of the lower priorities. In addition, complete disassembly may not be desired, required, or even possible, resulting in only partial disassembly being conducted. The result may be a disassembly sequence that readily satisfies the decision-maker's primary requirements, but at the expense of an unbalanced line. However, obtaining the decision-maker's primary requirements may not sufficiently justify exceptionally poor balance. Alternatively, the difference between a balanced disassembly line and one that is unbalanced may be so insignificant that a focus purely on balance may obfuscate the benefits of considering other criteria. Therefore, metrics are needed to evaluate the merits of all considered criteria, including the level of balance (or unbalance). In this paper, a multicriteria benchmark dataset and associated metrics are developed for use in quantitatively evaluating an unbalanced paced disassembly line. Metrics and experimental data for assessing unbalanced disassembly lines
Seamus M. McGovern, Surendra M. Gupta
International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 82 - 112
Disassembly lines are inherently multicriteria, with balance having the possibility of being one of the lower priorities. In addition, complete disassembly may not be desired, required, or even possible, resulting in only partial disassembly being conducted. The result may be a disassembly sequence that readily satisfies the decision-maker's primary requirements, but at the expense of an unbalanced line. However, obtaining the decision-maker's primary requirements may not sufficiently justify exceptionally poor balance. Alternatively, the difference between a balanced disassembly line and one that is unbalanced may be so insignificant that a focus purely on balance may obfuscate the benefits of considering other criteria. Therefore, metrics are needed to evaluate the merits of all considered criteria, including the level of balance (or unbalance). In this paper, a multicriteria benchmark dataset and associated metrics are developed for use in quantitatively evaluating an unbalanced paced disassembly line.

]]> 10.1504/IJMTM.2011.042110 International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 82 - 112 Seamus M. McGovern Surendra M. Gupta US DOT National Transportation Systems Centre, 55 Broadway, Cambridge, Massachusetts 02142-1093, USA. ' Laboratory for Responsible Manufacturing, 334 Snell Engineering Centre, Department of Mechanical and Industrial Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115-5000, USA paced production systems disassembly sequencing benchmark dataset metrics reverse manufacturing modelling unbalanced lines multicriteria decision making MCDM. 2011-08-26T23:20:50-05:00 23 1/2 82 112 2011-08-26T23:20:50-05:00 http://www.inderscience.com/link.php?id=42111 It is well known that in the automobile industry there is a need to maintain a certain order in the vehicles as they pass through the assembly line. Sequences have to be built according to each vehicle's 'options', each one requiring different resources and production time, the objective being to avoid exceeding the maximum human and facility potential. The problem resides in the complexity of ordering, at the same time, the presence or absence of each and every truly restrictive option. For this type of problem there are no efficient polynomial resolution algorithms, and heuristic methods are the most widely used. This paper uses two global heuristic optimisation methods such as simulated annealing and genetic algorithms applied to the specific problem of finding the optimum sequence for unbalanced car assembly lines. The best optimisation parameters are calculated using the experimental design method. The paper also proposes a new cost function to better represent car scheduling problem constraints. This cost function and the optimisation methods have proved their efficiency in the scheduling of real production data for a highly flexible car manufacturing assembly line (PSA Peugeot Citroen car assembly line at Vigo, Spain). Simulated annealing vs. genetic algorithms applied using a new cost function for the car sequencing problem
Juan J. Areal, Ricardo Marin Martin, Julio Garrido Campos
International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 113 - 136
It is well known that in the automobile industry there is a need to maintain a certain order in the vehicles as they pass through the assembly line. Sequences have to be built according to each vehicle's 'options', each one requiring different resources and production time, the objective being to avoid exceeding the maximum human and facility potential. The problem resides in the complexity of ordering, at the same time, the presence or absence of each and every truly restrictive option. For this type of problem there are no efficient polynomial resolution algorithms, and heuristic methods are the most widely used. This paper uses two global heuristic optimisation methods such as simulated annealing and genetic algorithms applied to the specific problem of finding the optimum sequence for unbalanced car assembly lines. The best optimisation parameters are calculated using the experimental design method. The paper also proposes a new cost function to better represent car scheduling problem constraints. This cost function and the optimisation methods have proved their efficiency in the scheduling of real production data for a highly flexible car manufacturing assembly line (PSA Peugeot Citroen car assembly line at Vigo, Spain).

]]> 10.1504/IJMTM.2011.042111 International Journal of Manufacturing Technology and Management, Vol. 23, No. 1/2 (2011) pp. 113 - 136 Juan J. Areal Ricardo Marin Martin Julio Garrido Campos Departamento de Ingenieria de Sistemas y Automatica, E.T.S. Ingenieros Industriales 36200, Vigo University, Spain. ' Departamento de Ingenieria de Sistemas y Automatica, E.T.S. Ingenieros Industriales 36200, Vigo University, Spain. ' Departamento de Ingenieria de Sistemas y Automatica, E.T.S. Ingenieros Industriales 36200, Vigo University, Spain automotive assembly lines scheduling genetic algorithms simulated annealing optimisation cost functions automobile industry optimum sequences unbalanced assembly lines unbalanced lines flexible assembly systems FAS Spain. 2011-08-26T23:20:50-05:00 23 1/2 113 136 2011-08-26T23:20:50-05:00