Identification approach for bottleneck clusters in a job shop based on theory of constraints and sensitivity analysis

Author(s):  
Qi Lei ◽  
Tong Li

Manufacturing systems are constrained by one or more bottlenecks. Reducing bottlenecks improves the entire system. Finding bottlenecks, however, is a difficult task. In this study, a new bottleneck detection method based on theory of constrains and sensitivity analysis is presented to overcome the disadvantages of existing bottleneck identification methods for a job shop. First, a bottleneck index matrix is obtained by examining the sensitivity of system production performance to the capacity of each machine. Technique for order preference by similarity to ideal solution is then employed to calculate the comprehensive bottleneck index of each machine. Based on the calculation result, bottleneck machine clusters under different hierarchies are obtained through hierarchical cluster analysis. The designed identification approach, as a prior-to-run method, can identify bottleneck machine clusters under different hierarchies before the overall system circulation, thereby providing good guidance for subsequent production optimization. Finally, a set of job-shop scheduling problem benchmarks with different scales is selected for comparison between the proposed approach and existing approaches, such as, the shifting bottleneck detection method, the bottleneck detection method based on orthogonal experiment, and the bottleneck cluster identification method. By comparison, the proposed approach is proven to be credible and superior.

Author(s):  
Lin Li ◽  
Dragan Djurdjanovic ◽  
Jun Ni

Maintenance operations have a direct influence on production performance in manufacturing systems. Maintenance task prioritization is crucial and important, especially when availability of maintenance resources is limited. The decision on task assignment is often made through heuristic methods or experience, which could cause more downtime and the production losses. In this paper, a new maintenance task prioritization policy based on data driven bottleneck detection and reliability-based maintenance opportunity window calculation is introduced. An experiment in simulation of a real production line shows the proposed policy is able to improve the system reliability, increase the throughput and minimize the total cost of system operation.


10.6036/9917 ◽  
2021 ◽  
Vol 96 (5) ◽  
pp. 455-459
Author(s):  
MAHDI NADERI ◽  
ANTONIO FERNÁNDEZ ULLOA ◽  
JOSÉ ENRIQUE ARES GÓMEZ ◽  
GUSTAVO PELÁEZ LOURIDO

Despite the growing importance that is being given to the concepts of sustainability in many areas, not only in industry but also in the economy and public opinion in general, until now, most research has focused, practically, on the analysis of the concepts, but has not addressed, in a comprehensive way, its impact in decision making probably due to the complex relations of interdependence between its different aspects. In this context, MAPSAM (Methodology for the Assessment of Sustainability in Manufacturing Processes and Systems) was created to help the decision-making process, allowing a conscious and transparent assessment by administrators and managers at the different levels of the structure of companies and organisations. This article explains its development and application in a "job shop" type manufacturing system with an approach that allows the integration of economic, environmental and social criteria. MAPSAM is based on the use of various techniques and tools to quantify the importance of each aspect of sustainability and it has been applied in other production environments, being implemented in different systems, analysing their ease of use and evaluating their behaviour. The objective is to show how it helps to make operational, tactical and strategic decisions in the management on these type of manufacturing companies and, specifically, in this contribution we want to highlight its versatility and applicability, by validating it in a certain type of layout. With this new application, MAPSAM increases its possibilities as an innovative instrument that allows companies to make conscious and sustainable decisions in order to be more efficient, fair, supportive and respectful of the environment. Keywords: Manufacturing System, Simulation, Decision Support, Sustainable Production, Decision-Making


2021 ◽  
Author(s):  
Hamid Pourpak ◽  
Samuel Taubert ◽  
Marios Theodorakopoulos ◽  
Arnaud Lefebvre-Prudencio ◽  
Chay Pointer ◽  
...  

Abstract The Diyab play is an emerging unconventional play in the Middle East. Up to date, reservoir characterization assessments have proved adequate productivity of the play in the United Arab Emirates (UAE). In this paper, an advanced simulation and modeling workflow is presented, which was applied on selected wells located on an appraisal area, by integrating geological, geomechanical, and hydraulic fracturing data. Results will be used to optimize future well landing points, well spacing and completion designs, allowing to enhance the Stimulated Rock Volume (SRV) and its consequent production. A 3D static model was built, by propagating across the appraisal area, all subsurface static properties from core-calibrated petrophysical and geomechanical logs which originate from vertical pilot wells. In addition, a Discrete Fracture Network (DFN) derived from numerous image logs was imported in the model. Afterwards, completion data from one multi-stage hydraulically fracked horizontal well was integrated into the sector model. Simulations of hydraulic fracturing were performed and the sector model was calibrated to the real hydraulic fracturing data. Different scenarios for the fracture height were tested considering uncertainties related to the fracture barriers. This has allowed for a better understanding of the fracture propagation and SRV creation in the reservoir at the main target. In the last step, production resulting from the SRV was simulated and calibrated to the field data. In the end, the calibrated parameters were applied to the newly drilled nearby horizontal wells in the same area, while they were hydraulically fractured with different completion designs and the simulated SRVs of the new wells were then compared with the one calculated on the previous well. Applying a fully-integrated geology, geomechanics, completion and production workflow has helped us to understand the impact of geology, natural fractures, rock mechanical properties and stress regimes in the SRV geometry for the unconventional Diyab play. This work also highlights the importance of data acquisition, reservoir characterization and of SRV simulation calibration processes. This fully integrated workflow will allow for an optimized completion strategy, well landing and spacing for the future horizontal wells. A fully multi-disciplinary simulation workflow was applied to the Diyab unconventional play in onshore UAE. This workflow illustrated the most important parameters impacting the SRV creation and production in the Diyab formation for he studied area. Multiple simulation scenarios and calibration runs showed how sensitive the SRV can be to different parameters and how well placement and fracture jobs can be possibly improved to enhance the SRV creation and ultimately the production performance.


2016 ◽  
Vol 78 (7) ◽  
Author(s):  
Cheng Ying, Nyeoh ◽  
Hasnida Ab-Samat ◽  
Shahrul Kamaruddin

Facility layout design has an important function in manufacturing systems because it affects manufacturing costs, work in progress, lead times, and production output. This study presents facility layout designs for multi-product and small-lot-sized production lines. This research focuses on the development and analysis of layout alternatives on the basis of performance measures and aims to improve production efficiency. Thus, the tools and techniques available for the layout designed were investigated. Related data were collected, and alternative layouts were developed using the WITNESS simulation software. Finally, the alternative layouts were ana1yzed and evaluated using the analytic hierarchy process to identify the best possible layout. Two important parameters observed in the alternative layouts: the ability to produce a desired output and the flexibility of each layout coherent with the fluctuation of product demands in the industry. Results from analysis shows that suggested Model 3 with the combination of flow line and job shop configurations is the most suitable layout. This model has the highest machine utilization rate and the highest labour utilization rate yet requires only 21 operators, the lowest number of workers. For future work, this type of layout should be tested with different variation in lot sizes.


Author(s):  
Pingyu Jiang ◽  
Wei Cao

As a key advanced manufacturing technology in next generation manufacturing systems, radio frequency identification (RFID) technology is considered to be one of the most promising technological innovations with the potential to increase visibility and improve efficiency. Therefore, research about RFID and its applications are increasing by blasting with all kinds of RFID models in various fields, especially in manufacturing. By introducing RFID technology into the job-shop floor, this paper proposes a systematic RFID-driven graphical formalized deduction model (rfid-GFDM) for describing the time-sensitive state and position changes of work-in-progress (WIP) material flows and guiding where to deploy RFID devices and how to use them for collecting real-time on-site data. Four steps including RFID configuration based on the process flow model, state blocks model, automatic event generation, and extended event-driven model are proposed one by one to support the implementation of rfid-GFDM. The nature of RFID technology is revealed, too. A use case about a computer numerical control (CNC) milling system is studied, and it demonstrates the feasibility of the proposed model. Finally, the possibility of popularizing the model to other field is discussed, too. It is expected to establish a normative RFID modeling method that will facilitate the convenience of RFID applications in a broad scope.


Author(s):  
Abdul Salam Khan ◽  
Khawer Naeem ◽  
Raza Ullah Khan

An abrupt change requires a robust and flexible response from a manufacturing system. Dedicated Manufacturing System (DMS) has been a long practiced taxonomy for mass production and minimum varieties. In contrast, Flexible Manufacturing System (FMS) has been introduced for responding to quantity as well as variety issues. This study considers both production taxonomics by using a multi objective model of cost and time. An Integer Linear Programming (ILP) formulation is presented and subsequently validated. The analysis procedure is administered in two phases. In the first phase, comparison of production cost and process time in DMS and FMS is presented. The model is implemented by using an exact solution approach and results show that FMS is a viable option, compared to DMS, according to the criteria of cost, time, and productivity. In the second phase, sensitivity analysis is performed by using several FMS (n) and the impact of cells selection on the performance of system is studied. It is concluded that n=1 (single cell-based FMS) is more relevant for cost minimization; however, n = 6 is a suitable candidate for producing more quantity in given time horizon (process time minimization). Lastly, key findings are reported, and future research avenues are provided.


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