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1 – 10 of over 1000Shahrul Kamaruddin, Zahid A. Khan, Arshad Noor Siddiquee and Yee-Sheng Wong
As the manufacturing activities in today's industries are getting more and more complex, it is required for the manufacturing firm to have a good shop floor production scheduling…
Abstract
Purpose
As the manufacturing activities in today's industries are getting more and more complex, it is required for the manufacturing firm to have a good shop floor production scheduling to plan and schedule their production orders. An accurate scheduling is essential to any manufacturing firm in order to be competitive in global market. The paper aims to discuss these issues.
Design/methodology/approach
Two types of shop floors, job shop and cellular layout, were developed by using WITNESS simulation package. Consequently, the performance of forward scheduling and backward scheduling in both job shop and cellular layout was compared using simulation method, and the results were analyzed by using analysis of variance (ANOVA). Through analysis, the best scheduling approach and layout to be used by manufacturing firm in order to achieve the make-to-order (MTO) production and inventory strategy were reported.
Findings
The results from simulation show that backward scheduling in job shop layout has the lowest average throughput time, lowest lateness, and highest labour productivity than forward scheduling. While in cellular layout, forward scheduling has the lowest average throughput time, lowest lateness, and highest labour productivity than backward scheduling in all conditions. It shows that the performance of scheduling approach is different in each production layout.
Originality/value
Suitable scheduling approach is needed in manufacturing industry as to maximize production rate and optimize machine and process capability. This paper presents an empirical study about the assembly process of radio cassette player of one manufacturing industry in order to investigate the impact of variety of orders and different number of two workers on the performance of production scheduling approach. Forward scheduling and backward scheduling are used to schedule the production orders.
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Vijay R. Kannan and Soumen Ghosh
Proposes a virtual cellular manufacturing approach to implementing cellular manufacturing systems that combines the set‐up efficiency typically obtained by traditional cellular…
Abstract
Proposes a virtual cellular manufacturing approach to implementing cellular manufacturing systems that combines the set‐up efficiency typically obtained by traditional cellular manufacturing or group technology systems with the flexibility of a job shop. Unlike traditional cellular systems in which the shop is physically designed as a series of cells, cells are formed within a shop utilizing a process layout using scheduling mechanisms. The result is the formation of cells that are temporary and logical (virtual) in nature, allowing them to be more responsive to changes in demand patterns. Simulation runs comparing this approach to production using traditional cellular and job shop approaches indicate that this new approach yields significantly better shop performance over a range of operating conditions.
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Scott M. Shafer and Jack R. Meredith
Cellular and functional layouts were investigated under a varietyof real‐world conditions via a two‐stage computer simulation study. Inthe first stage, simulation models were…
Abstract
Cellular and functional layouts were investigated under a variety of real‐world conditions via a two‐stage computer simulation study. In the first stage, simulation models were developed for three actual companies. Six different cell formation procedures were used to develop the cellular layouts and CRAFT was used to develop the functional layout. The following six variables were used to measure shop performance: average flow time, maximum flow time, average distance travelled by a batch, average work‐in‐process level, the maximum level of work‐in‐process, and the longest average queue. Factors observed in the first stage of the study that appear to make cellular manufacturing less beneficial than might otherwise be expected were found to be small batch sizes, a small number of different machines the parts require in their processing, short processing times per part, the existence of bottleneck machines (i.e. machines with insufficient capacity), and the absence of natural part families (i.e. sets of parts with similar processing requirements). In the second stage of this study, earlier assumptions associated with sequence‐dependent setup times and move time delays were relaxed. These two parameters were identified as important factors as well.
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Ravi Kumar and Surya Prakash Singh
In today’s competitive market, product demand and its mix frequently vary due to various uncertainties, which thus imparts the overall manufacturing cost. Furthermore…
Abstract
Purpose
In today’s competitive market, product demand and its mix frequently vary due to various uncertainties, which thus imparts the overall manufacturing cost. Furthermore, uncertainties also impart the layout design in manufacturing industries in the long run. Therefore, the layout design needs to capture the possibility of uncertainties, and these uncertainties must be captured while designing the layout of a facility. Hence, an efficient facility layout design minimizes the manufacturing cost and lead time. The purpose of this paper is to propose a cellular layout design for a tower manufacturing industry.
Design/methodology/approach
The paper develops an embedded simulated annealing-based meta-heuristic to solve proposed cellular layout under different scenarios considering single and multi-time periods for tower manufacturing industry. A comparative study is also performed to analyze comparison among static cellular layout, a dynamic cellular layout or a robust stochastic cellular layout for the tower manufacturing industry.
Findings
The current layout of the industry is a process layout. Here, the layout for a tower manufacturing industry is proposed under SCFLP, DCFLP and RSCFLP. The proposed models and solution methodology is tested using six scenarios with different combination of time periods. Lastly, OFV value obtained for all the scenarios is compared, and it is found that RSCFLP outruns other SCFLP and DCFLP for a tower manufacturing industry. Based on the above study, it is also concluded that RSCFLP is an efficient and effective layout in tower manufacturing industry.
Originality/value
The paper proposes a cellular layout design for a tower manufacturing industry. The cellular layout design is found to be preferred over the traditional layout as it reduces material handling cost, manufacturing lead time and hazards. Moreover, it enhances productivity and quality.
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Fahad Al‐Mubarak, Basheer M. Khumawala and Cem Canel
This paper is aimed at comparing cellular manufacturing with focused cellular manufacturing. We define focused cellular manufacturing as a layout scheme that groups components by…
Abstract
This paper is aimed at comparing cellular manufacturing with focused cellular manufacturing. We define focused cellular manufacturing as a layout scheme that groups components by end‐items and forms cells of machines to fabricate and assemble end‐items. It is not classified as a cellular manufacturing layout since it does not attempt to take advantage of process similarities. It also is not classified as a flow shop since there are no machines dedicated to individual operations and the machines are not arranged in a series. In addition, this research includes batching and assemble times in its criteria which few researchers in this area have done. The results indicate that the focused cellular manufacturing scheme has a batching advantage. This advantage out‐weighed the set‐up time reduction advantage of the cellular manufacturing scheme for average end‐item completion times and average work‐in‐process inventory levels. The cellular manufacturing scheme overcame the batching advantage only when there were small batch sizes or large set‐up time magnitudes.
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Faizul Huq, Douglas A. Hensler and Zubair M. Mohamed
Contrasts functional layouts and cellular layouts with regard to the effects of set‐up time reduction and lot size on flow time and through‐put. The structural environment for the…
Abstract
Contrasts functional layouts and cellular layouts with regard to the effects of set‐up time reduction and lot size on flow time and through‐put. The structural environment for the functional analysis is an efficient functional system with a staged sequence of four machine centers with unidirectional flow and no backtracking. The structural environment for the cellular analysis is a partitioned cell consisting of one machine from each of the four machine types with unidirectional flow and no backtracking. Simulation models produce robust results for eight lot size levels and one (functional model) and seven (cellular model) set‐up time reduction levels. The results contrast the effectiveness of the two manufacturing approaches under differing input conditions. Shows that the choice between the functional structure and the cellular structure significantly affects through‐put at lot sizes up to 55, while for lot sizes of 60 and above there is no significant effect. The study also confirms previous results regarding the effect of manufacturing structure choice on flow time.
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Jaydeep Balakrishnan and Chun Hung Cheng
The purpose of this research paper is to discuss cellular manufacturing is discussed under conditions of changing product demand. Traditional cell formation procedures ignore any…
Abstract
Purpose
The purpose of this research paper is to discuss cellular manufacturing is discussed under conditions of changing product demand. Traditional cell formation procedures ignore any changes in demand over time from product redesign and other factors. However given that in today's business environment, product life cycles are short, a framework is proposed that creates a multi‐period cellular layout plan including cell redesign where appropriate.
Design/methodology/approach
The framework is illustrated using a two‐stage procedure based on the generalized machine assignment problem and dynamic programming. This framework is conceptually compared to virtual cell manufacturing, which is useful when there is uncertainty in demand rather than anticipated changes in demand. A case study is used to explain how the concept would work in practice.
Findings
One major characteristic of the proposed method is that it is flexible enough to incorporate existing cell formation procedures. It is shown through an example problem that the proposed two‐stage method is better than undergoing ad hoc layout changes or ignoring the demand changes when shifting or cell rearrangement costs exist. It also sheds some insight into cellular manufacturing under dynamic conditions.
Originality/value
This paper should be useful to both researchers and practitioners who deal with demand changes in cellular manufacturing.
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Simulation experiment was employed to investigate the schemes for coordinating JIT practices to promote performance upgrade in a job shop environment with the pull system.
Abstract
Purpose
Simulation experiment was employed to investigate the schemes for coordinating JIT practices to promote performance upgrade in a job shop environment with the pull system.
Design/methodology/approach
The four related essential JIT practices (job shop JIT practices) investigated include: cellular manufacturing (CM), operations overlapping (OPOVR), reduction of set‐up/processing time variability (variability reduction) and set‐up time reduction (STR).
Findings
Experiment findings suggest that coordination of CM and STR should be given the priority. While the extent of STR effected by CM substantially influences the efficacy of adopting a cellular layout, the choice of adopting a functional layout (FL) is more likely to be affected by the STR resulted from improvement of set‐up operations (set‐up improvement). Variability reduction tends to be more effective for a cellular layout. For a cellular layout without OPOVR, the effectiveness of reducing set‐up time variability is prominent and almost impervious to the extent of set‐up improvement. For a FL, the effect of variability reduction is minor; reduction of set‐up time variability is effective in this case only for a set‐up to processing time ratio of 20 or larger. The findings of this study do not justify the implementation of OPOVR in the shop environment, even with the support of the other three job shop JIT practices.
Originality/value
This study is notable in integrating STR into the job shop JIT practices to achieve overall performance improvement. In addition, the resulting strategies for variability reduction are essential for adapting the pull system to job shop manufacturing. Therefore, the findings of this study form systematic guidelines enabling exercise of the job shop JIT practices coherently to promote reform of job shop manufacturing.
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Kerstin Sailer and Matt Thomas
This research provides a new perspective on the long-standing debate of open-plan versus cellular offices. It analyzes the effects of workplace layouts on organizational outputs…
Abstract
Purpose
This research provides a new perspective on the long-standing debate of open-plan versus cellular offices. It analyzes the effects of workplace layouts on organizational outputs such as innovation, efficiency and privacy by considering the physical space of an organization alongside its organizational structure. This socio-spatial approach draws on correspondence theory originating from space syntax to understand the potential for unplanned encounters between diverse groups of people.
Design/methodology/approach
Three different organizations are studied, two open-plan and one cellular office. Floor and seating plans are analyzed to calculate the degree of correspondence between the spatial and conceptual closeness of people. Demands for each organization are derived from semi-structured interviews and publicly available information.
Findings
The three studied organizations present very different degrees of openness toward others in ways that challenge conventional views of cellular and open-plan offices. In each case, the degree of correspondence matches the demands placed on the organization, and hence, providing a relatively good fit between the organization and interior environment.
Research limitations/implications
A larger sample of open-plan and cellular offices would be useful to consider in further research.
Practical implications
Managers can use the concept of correspondence to generate the appropriate degree of unplanned encounters between the right sets of people in order to achieve the best organization-environment fit.
Originality/value
The main innovation of this paper lies in its socio-spatial approach, considering physical space alongside managerial, organizational choices.
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Abdessalem Jerbi, Hédi Chtourou and Aref Y. Maalej
A number of simulation studies were conducted by several researchers in order to compare performances of cellular and functional layouts. The methodologies used by these studies…
Abstract
Purpose
A number of simulation studies were conducted by several researchers in order to compare performances of cellular and functional layouts. The methodologies used by these studies either present several objectivity lacks or are highly time‐consuming. The purpose of this paper is to propose a novel and objective methodology, based on the coupling of simulation and the Taguchi method.
Design/methodology/approach
Simulation models for both layouts are first developed. Simulations are then conducted following a standard Taguchi orthogonal array. Subsequently, the obtained results are analyzed using the analysis of variance technique. Finally, a mathematical model is built, and validated by the confirmation test.
Findings
The proposed comparison method permitted to obtain a valid mathematical model used to predict the superiority rank of the two layouts within the scope of the paper.
Originality/value
This paper presents a novel objective methodology for comparing functional and cellular layouts.
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