Bottleneck-based opportunistic maintenance model for series production systems

2015 ◽  
Vol 21 (1) ◽  
pp. 70-88 ◽  
Author(s):  
Binghai Zhou ◽  
Jiadi Yu ◽  
Jianyi Shao ◽  
Damien Trentesaux

Purpose – The purpose of this paper is to develop a bottleneck-based opportunistic maintenance (OM) model for the series production systems with the integration of the imperfect effect into maintenance activities. Design/methodology/approach – On the analysis of availability and maintenance cost, preventive maintenance (PM) models subjected to imperfect maintenance for different equipment types are built. And then, a cost-saving function of OM is established to find out an optimal OM strategy, depending on whether the front-bottleneck machines adopt OM strategy or not. A numerical example is given to show how the proposed bottleneck-based OM model proceeded. Findings – The simulation results indicate that the proposed model is better than the methods to maintain the machines separately and the policy to maintain all machines when bottleneck machine reaches its reliability threshold. Furthermore, the relationship between OM strategy and corresponding parameters is identified through sensitivity analysis. Practical implications – In practical situations, the bottleneck machine always determines the throughput of the whole series production system. Whenever a PM activity is carried out on the bottleneck machine, there will be an opportunity to maintenance other machines. Under such circumstances, findings of this paper can be utilized for the determination of optimal OM policy with the objective of minimizing total maintenance cost of the system. Originality/value – This paper presents a bottleneck-based OM optimization model with the integration of the imperfect effect as a new method to schedule maintenance activities for a series production system with buffers. Furthermore, to the best of the knowledge, this paper presents the first attempt to considering the bottleneck constraint on system capacity and diverse types of machines as a means to minimize the maintenance cost and ensure the system throughput.

2015 ◽  
Vol 6 (4) ◽  
pp. 60-69 ◽  
Author(s):  
Sławomir Kłos ◽  
Peter Trebuna

Abstract This paper proposes the application of computer simulation methods to support decision making regarding intermediate buffer allocations in a series-parallel production line. The simulation model of the production system is based on a real example of a manufacturing company working in the automotive industry. Simulation experiments were conducted for different allocations of buffer capacities and different numbers of employees. The production system consists of three technological operations with intermediate buffers between each operation. The technological operations are carried out using machines and every machine can be operated by one worker. Multi-work in the production system is available (one operator operates several machines). On the basis of the simulation experiments, the relationship between system throughput, buffer allocation and the number of employees is analyzed. Increasing the buffer capacity results in an increase in the average product lifespan. Therefore, in the article a new index is proposed that includes the throughput of the manufacturing system and product life span. Simulation experiments were performed for different configurations of technological operations.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jagan Mohan Reddy K. ◽  
Neelakanteswara Rao A. ◽  
Krishnanand Lanka ◽  
PRC Gopal

Purpose Pull production systems have received much attention in the supply chain management environment. The number of Kanbans is a key decision variable in the pull production system as it affects the finished goods inventory (FGI) and backorders of the system. The purpose of this study is to compare the performance of the fixed and dynamic Kanban systems in terms of operational metrics (FGI and backorders) under the demand uncertainty. Design/methodology/approach In this paper, the system dynamics (SD) approach was used to model the performance of fixed and dynamic Kanban based production systems. SD approach has enabled the feedback mechanism and is an appropriate tool to incorporate the dynamic control during the simulation. Initially, a simple Kanban based production system was developed and then compared the performance of production systems with fixed and dynamic controlled Kanbans at the various demand scenarios. Findings From the present study, it is observed that the dynamic Kanban system has advantages over the fixed Kanban system and also observed that the variation in the backorders with respect to the demand uncertainty under the dynamic Kanban system is negligible. Research limitations/implications In a just-in-time production system, the number of Kanbans is a key decision variable. The number of Kanbans is mainly depended on the demand, cycle time, safety stock factor (SSF) and container size. However, this study considered only demand uncertainty to compare the fixed and dynamic Kanban systems. This paper further recommends researchers to consider other control variables which may influence the number of Kanbans such as cycle time, SSF and container size. Originality/value This study will be useful to decision-makers and production managers in the selection of the Kanban systems in uncertain demand applications.


2017 ◽  
Vol 25 (4) ◽  
pp. 454-474
Author(s):  
Jacqueline Cope ◽  
Francois Siewe ◽  
Feng Chen ◽  
Leandros Maglaras ◽  
Helge Janicke

Purpose This study is an exploration of areas pertaining to the use of production data in non-production environments. During the software development life cycle, non-production environments are used to serve various purposes to include unit, component, integration, system, user acceptance, performance and configuration testing. Organisations and third parties have been and are continuing to use copies of production data in non-production environments. This can lead to personal and sensitive data being accidentally leaked if appropriate and rigorous security guidelines are not implemented. This paper aims to propose a comprehensive framework for minimising data leakage from non-production environments. The framework was evaluated using guided interviews and was proven effective in helping organisation manage sensitive data in non-production environments. Design/methodology/approach Authors conducted a thorough literature review on areas related to data leakage from non-production systems. By doing an analysis of advice, guidelines and frameworks that aims at finding a practical solution for selecting and implementing a de-identification solution of sensitive data, the authors managed to highlight the importance of all areas related to sensitive data protection. Based on these areas, a framework was proposed which was evaluated by conducting set of guided interviews. Findings This paper has researched the background information and produced a framework for an organisation to manage sensitive data in its non-production environments. This paper presents a proposed framework that describes a process flow from the legal and regulatory requirements to data treatment and protection, gained through understanding the organisation’s business, the production system, the purpose and the requirements of the non-production environment. The paper shows that there is some conflict between security and perceived usability, which may be addressed by challenging the perceptions of usability or identifying the compromise required. Non-production environments need not be the sole responsibility of the IT section, they should be of interest to the business area that is responsible for the data held. Originality/value This paper proposes a simplified business model and framework. The proposed model diagrammatically describes the interactions of elements affecting the organisation. It highlights how non-production environments may be perceived as separate from the business systems, but despite the perceptions, these are still subject to the same legal requirements and constraints. It shows the interdependency of data, software, technical infrastructure and human interaction and how the change of one element may affect the others. The proposed framework describes the process flow and forms a practical solution in assisting the decision-making process and providing documentary evidence for assurance and audit purposes. It looks at the requirements of the non-production system in relation to the legal and regulatory constraints, as well as the organisational requirements and business systems. The impact of human factors on the data is also considered to bring a holistic approach to the protection of non-production environments.


2016 ◽  
Vol 83 (5) ◽  
Author(s):  
Vaibhav C. Gole ◽  
Rebecca Woodhouse ◽  
Charles Caraguel ◽  
Talia Moyle ◽  
Jean-Loup Rault ◽  
...  

ABSTRACT The current study investigated the effect of environmental stressors (i.e., weather changes) on Salmonella shedding in free-range production systems and the correlations with behavioral and physiological measures (i.e., fecal glucocorticoid metabolites). This involved longitudinal and point-in-time surveys of Salmonella shedding and environmental contamination on four commercial free-range layer farms. The shedding of Salmonella was variable across free-range farms and in different seasons. There was no significant effect of season on the Salmonella prevalence during this investigation. In this study, the combined Salmonella most probable number (MPN) counts in environmental (including feces, egg belt, dust, nest box, and ramp) samples were highest in samples collected during the summer season (4th sampling, performed in February). The predominant serovars isolated during this study were Salmonella enterica serovar Mbandaka and Salmonella enterica serovar Typhimurium phage types 135 and 135a. These two phage types were involved in several egg product-related Salmonella outbreaks in humans. Multilocus variable-number tandem-repeat analysis (MLVA) results indicated that MLVA types detected from human food poisoning cases exhibited MLVA patterns similar to the strains isolated during this study. All Salmonella isolates (n = 209) were tested for 15 different genes involved in adhesion, invasion, and survival of Salmonella spp. We also observed variations for sopA, ironA, and misL. There were no positive correlations between fecal corticosterone metabolite (FCM) and Salmonella prevalence and/or shedding in feces. Also, there were no positive correlations between Salmonella prevalence and Salmonella count (log MPN) and any of the other welfare parameters. IMPORTANCE In this study, the welfare of laying hens and Salmonella shedding were compared over a prolonged period of time in field conditions. This study investigated the long-term shedding of Salmonella serovars in a free-range egg production system. Given that there is increasing demand for free-range eggs, it is essential to understand the risks associated with such a production system.


Author(s):  
Amanuel Berhe ◽  
Solomon Abera Bariagabre ◽  
Mulubrhan Balehegn

Purpose Different livestock production systems contribute to globally Greenhouse gas emission (GHG) emission differently. The aim of this paper is to understand variation in emission in different production systems and it is also important for developing mitigation interventions that work for a specific production system. Design/methodology/approach In this study, the authors used the Global Livestock Environmental Assessment interactive model (GLEAM-i) to estimate the GHG emission and emission intensity and tested the effectiveness of mitigation strategies from 180 farms under three production systems in northern Ethiopia, namely, pastoral, mixed and urban production systems. Findings Production systems varied in terms of herd composition, livestock productivity, livestock reproductive parameters and manure management systems, which resulted in difference in total GHG emission. Methane (82.77%) was the largest contributor followed by carbon dioxide (13.40%) and nitrous oxide (3.83%). While both total carbon dioxide and methane were significantly higher (p < 0.05) in urban production system than the other systems emission intensities of cow’s milk and goat and sheep’s meat were lower in urban systems. Improvement in feed, manure management and herd parameters resulted in reduction of total GHG emission by 30, 29 and 21% in pastoral, mixed and urban production systems, respectively. Originality/value This study is a first time comparison of the GHG emission production by various production systems in northern Ethiopia. Moreover, it uses the GLEAM-i program for the first time in the ex ante settings for measuring and comparing emissions as well as for developing mitigation scenarios. By doing so, it provides information on the various livestock production system properties that contribute to the increase or decrease in GHG emission and helps in developing guidelines for low emission livestock production systems.


2019 ◽  
Vol 10 (3) ◽  
pp. 718-742 ◽  
Author(s):  
Diego Augusto de Jesus Pacheco ◽  
Isaac Pergher ◽  
José Antônio Valle Antunes Junior ◽  
Guilherme Luís Roehe Vaccaro

Purpose The purpose of this study is to compare different models integrating the TOC and Lean approaches. Design/methodology/approach The models of reference were identified through a comprehensive literature review. A qualitative and comparative analysis was carried out by pointing out the strengths, weaknesses and gaps of models integrating the TOC and Lean based on the production system requirements. Findings The findings indicate that these models can be improved by introducing aspects related to the system structure such as main key performance indicators, type of shop layout and performance metrics to evaluate the improvements implemented in the production system. The results provided evidence that the TOC and Lean are complementary approaches, and the individual gaps of each approach seem to be, in the most part, offset by the virtues of the other. Practical implications This study enables decision makers and industrial managers to evaluate the practices adopted in the production environment, as well as the use of the different set of continuous improvement practices. This article also minimizes the literature gap regarding whether and how integrated Lean and TOC approach can be used in the firms. Originality/value This study contributes to the body of literature on Lean by comparing three different models integrating Lean and the TOC. Furthermore, a research agenda is suggested for future research aimed at developing new models integrating both approaches, aiming to increase the competitiveness of the production systems.


2016 ◽  
Vol 33 (2) ◽  
pp. 267-283 ◽  
Author(s):  
Lina Stålberg ◽  
Anders Fundin

Purpose – The purpose of this paper is to examine how holistic improvement work can be organized and what challenges can be observed in the process of adopting a holistic perspective on production system improvement. Design/methodology/approach – A qualitative case study and a questionnaire have been carried out. Data for the case study has been collected through semi-structured interviews, archived documents and participatory observations. The questionnaire was done in order to increase the generalizability of the findings from the case study and further validate the conclusions. Findings – The improvement work at the case company is organized as a continuous improvement approach in a Lean Production system in the form of a company-specific production system (XPS), in which two other improvement approaches are incorporated. Some of the identified challenges are: the establishment of a holistic perspective on improvement opportunities; the development of a process to update the production strategy; the continuous update of the Operational Management System during the XPS implementation; aggregating measures for the improvement work and measuring the effect of improvement work. Research limitations/implications – As the current case study is limited to one case company, future research is interested in expanding to other production systems contexts for further validation. Originality/value – The present study offers an increased understanding of the integration difficulties of improvement work that many production companies face regarding operational effectiveness, and based on the findings, some implications for management are presented.


2011 ◽  
Vol 421 ◽  
pp. 617-624 ◽  
Author(s):  
Wen Rui Hou ◽  
Zu Hua Jiang

This paper proposes an opportunistic maintenance policy for the multi-unit series production system, which is on the basis of the failure rate analysis. When system halts for performing preventive maintenance or opportunistic maintenance, the alternative decision of replacement and repair is made by economic evaluation of two types of maintenance actions. The optimal preventive maintenance plans in a finite time horizon can be obtained by adjusting the preventive and opportunistic maintenance threshold. A numerical example is given for illustrating the applications of the policy.


2019 ◽  
Vol 69 (5) ◽  
pp. 1009-1032 ◽  
Author(s):  
Panagiotis H. Tsarouhas

Purpose As overall equipment effectiveness (OEE) is a metric to estimate equipment effectiveness of production systems, the purpose of this paper is to identify strategic management tools and techniques based on OEE assessment of the ice cream production line. Design/methodology/approach This paper presents the collection and the analysis of data for ice cream production under real working conditions. The data cover a period of eight months. A framework process to improve the OEE of an automated production system was proposed. Six major stoppage losses, i.e. equipment failure, setup and adjustment, idling and minor stoppage, reduced speed, defects in the process, and reduced yield, were examined with the help of Pareto analysis. In addition, the actual availability (A), performance efficiency (PΕ) and quality rate (QR) measures, together with the complete OEE for each working day, week and month of the production line were shown. Findings The main goal of the study is to identify major stoppage losses, in order to examine and improve the overall equipment efficiency (OEE) of the ice cream production line through the application of an adequate management, i.e. TPM approach. Based on the obtained results, maintenance management strategy and production planning have been suggested to improve their maintenance procedures and the productivity as well. Originality/value The proposed method can be applied to each automated production system. The main benefits of this method are the improvement of productivity, quality enhancement of products, the reduction of sudden breakdowns and the cost of maintenance. Moreover, the analysis provides a useful perspective and helps managers/engineers make better decisions on the operations management of the line, and suggestions for improvement were proposed and will be implemented accordingly.


2014 ◽  
Vol 20 (4) ◽  
pp. 453-470 ◽  
Author(s):  
Behnam Emami-Mehrgani ◽  
Sylvie Nadeau ◽  
Jean-Pierre Kenné

Purpose – The analysis of the optimal production and preventive maintenance with lockout/tagout planning problem for a manufacturing system is presented in this paper. The considered manufacturing system consists of two non-identical machines in passive redundancy producing one type of part. These machines are subject to random breakdowns and repairs. The purpose of this paper is to minimize production, inventory, backlog and maintenance costs over an infinite planning horizon; in addition, it aims to verify the influence of human reliability on the inventory levels for illustrating the importance of human error during the maintenance and lockout/tagout activities. Design/methodology/approach – This paper is different compared to other research projects on preventive maintenance and lockout/tagout. The influence of human error on lockout/tagout as well as on preventive maintenance activities are presented in this paper. The preventive maintenance policy depends on the machine age. For the considered manufacturing system the optimality conditions are provided, and numerical methods are used to obtain machine age-dependent optimal control policies (production and preventive maintenance rates with lockout/tagout). Numerical examples and sensitivity analysis are presented to illustrate the usefulness of the proposed approach. The system capacity is described by a finite-state Markov chain. Findings – The proposed model taking into account the preventive maintenance activities with lockout/tagout and human error jointly, instead of taking into account separately. It verifies the influence of human error during preventive maintenance and lockout/tagout activities on the optimal safety stock levels using an extension of the hedging point structure. Practical implications – The model proposed in this paper might be extended to manufacturing systems, but a number of conditions must be met to make effective use of it. Originality/value – The originality of this paper is to consider the preventive maintenance activities with lockout/tagout and human error simultaneously. The control policy is obtained in order to find the solution for the considered manufacturing system. This paper also brings a new vision on the importance of human reliability during preventive maintenance and lockout/tagout activities.


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