Download or read book Performance Analysis and Development of Pull type Production Control Strategies for Evolutionary Optimisation of Closed loop Supply Chains written by Jonathan Reinholt Jr Ebner and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this thesis is to establish a Closed-Loop Supply Chain (CLSC) design that is analysed through a series of simulation models, aimed at defining the highest performing production control strategy, whilst considering multiple related variables on both the forward and reverse flow of materials in manufacturing environments. Due to its stochastic nature, the reverse logistics side of the CLSC represents an increased source of variance for the inventory management and control strategies as it implies the erratic supply of returned materials, in addition to the very random customer demand, hence with highly variable inputs on both sides of the productive system, intrinsically inherent to this line of research. To test the operational performance of several pull-type production control strategies, a simulation-based research method was designed. The strategies experimented were: Hybrid Extended Kanban CONWIP special case (HEKC-II), Hybrid Kanban CONWIP (HKC), Dynamic Allocation Hybrid Extended Kanban CONWIP special case (DNC HEKC-II) and Dynamic Allocation Hybrid Kanban CONWIP (DNC HKC). All were tested in scenarios with high and low processing time variability and with 90% returned products and 40% returns from an open market system, therefore totaling 16 simulation models. Multi-objective evolutionary algorithms were utilised to generate the Pareto-optimum performance frontier with the objective of simultaneously minimising both performance metrics: The overall average work in progress (WIP) and the average backlog queue length (BL) for the entire CLSC. Processes used in the recovery and recycling of end of life manufactured goods were examined. This research method structures leading factors towards improved economic viability and sustainability of technologies required for the effective implementation of inventory control strategies on highly complex closed-loop supply chains with the focus on the performance metrics and optimum utilisation of resources available for the industry. The dynamic allocation strategies proved significant performance improvement, shifting the entire Pareto frontier forward with major advances on both metrics. Furthermore, it happened on all scenarios tested. The modified HEKC-II, with an optimisable parameter that enables it to be overwritten in a way that it can match the well-established HKC, also performed as originally intended and had better results than HKC in some cases, especially with the higher variability level. It also provided grounds for the suggested improvements and flexibilisation of the HEKC strategy. A major contribution of this thesis was the successful implementation of another advanced control methodology, entitled here the Intelligent Self-Designing Production Control Strategy, which provided maximum control performance. It consisted essentially of DNC HEKC-II with the following modifications: I) Extensive increase of dynamically allocated authorisation cards; II) Further anticipation of the time to trigger the change in the number of cards according to the finished goods buffer level, plus an acceleration/deceleration factor of this change; III) The capability of downsizing itself to become similar to HKC in an optimisation process if diverse production system conditions and variability would require. It displayed a very significant shift of the performance frontier.
Download or read book Production Management written by Yacob Khojasteh and published by CRC Press. This book was released on 2017-11-07 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inventory control is an essential task in production management. An effective inventory control can significantly reduce the holding cost and hence, total production cost. Selecting and implementing a suitable production control system plays an important role in inventory reduction and performance improvement of a production system. Since the introduction of Toyota’s just-in-time philosophy, pull control systems have been adopted by numerous companies worldwide, both in the manufacturing and service sectors. This book provides some recent developments in production management and presents modeling and analysis tools for pull production control systems. It contributes by combining theoretical findings and case study analysis results with a practical and contemporary view on how to effectively manage and control production systems. Each chapter in this book focuses on a specific topic in production control systems, allowing readers to identify the chapters that relate to their interests. More specifically, the book is presented in three sections. The first section focuses on the design and implementation aspects of the pull production control systems, as well as performance evaluation approaches for pull systems. The second section presents a recent and comprehensive literature review. Three different case studies on implementation of pull production control systems are presented in the last section. This book can be used as an essential source for students and scholars who need to specifically study the pull control systems. Since the superiority of these systems is controversial, the book can also provide an interesting and informative read for practitioners, managers, and employees who need to deepen their knowledge on pull production management systems.
Download or read book Production Control Systems written by Yacob Khojasteh and published by Springer. This book was released on 2015-08-21 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selecting a suitable production control policy is a challenging task for managers because the superiority of one control over the other is controversial. This book analyzes pull production systems and provides a guideline to choose and implement a proper control policy in production processes. By employing a proper control policy the maximum possible throughput of the production system can be achieved with the minimum work-in-process inventory. Kanban, CONWIP, and base-stock as wellknown pull control policies are analyzed and analytical comparisons among them in multistage serial and assembly production processes are presented. Illustrated by carefully chosen examples and supported by analytical solutions, discussions provided in the book clarify the complexity of the comparisons that show there is no general superiority among the control systems. Th e book explains which structural parameters decide the superiority of one control scheme to the others, and how they are related. Given a confi guration of parameters, such as processing times and number of cards employed in the system, the superior control policy can be selected.
Download or read book Engineering Production Control Strategies written by Christoph Karrer and published by Springer Science & Business Media. This book was released on 2012-02-25 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: Identifying and customizing suitable control strategies is a challenging task, especially when production systems have to cope with variable demands, forecast error, and unstable processes. The focus of this book lies on helping companies with complex and discrete production systems to tailor a production control strategy to their needs. Thereby, the mutual merits of “push” and “pull” systems are taken into account, leading to hybrid strategies. Consequently, the book addresses practitioners who are interested in looking behind the scenes and into the physics of production control. A real-life case study demonstrates the practical applicability of the presented framework.
Download or read book EVOLUTIONARY OPTIMISATION OF P written by Pik-Yin Mok and published by Open Dissertation Press. This book was released on 2017-01-27 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Evolutionary Optimisation of Production-control Systems" by Pik-yin, Mok, 莫碧賢, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: SUMMARY The production control of manufacturing systems is at the heart of the whole manufacturing process, and such control involves a series of real-time scheduling decisions regarding different discrete production operations. Thus, improving the effectiveness of production-control systems is of vital importance. The use of stochastic control theory to find the optimal or near-optimal solutions of production-control problems is greatly facilitated by using continuous-flow models to approximate the discrete flows in manufacturing systems. However, past research showed that such problems are very difficult to solve either analytically or numerically by such means. In order to simplify the problems, some restrictive assumptions (such as long-run constant demands and exponentially distributed machine failures) were made in this previous theoretical work, but even so analytical solutions were obtained only for simple systems containing single machines producing single product-types. Evolutionary algorithms are used in this thesis to develop practical solutions for these analytically intractable production-control problems in two different ways, namely, crisp-logic control and fuzzy-logic control. In the case of crisp-logic control, an evolutionary stochastic optimisation procedure is developed to estimate the optimal short-run inventory levels for finished-products and work-in-progress buffers (i.e., hedging points) for manufacturing systems with constant demands under closed-loop control. This methodology is illustrated by examples of manufacturing systems with different configurations (single machines, multiple machines, single product-types, and multiple product-types), and the results are validated by comparing them to the theoretically optimal i results (where such results are available). The evolutionarily optimised short-run inventory levels are also used to construct gain-scheduled adaptive controllers, and it is shown that such controllers can provide automatic closed-loop control for manufacturing systems with piecewise-constant demands. In the case of fuzzy-logic control, an evolutionary rule-induction design procedure is developed to optimise fuzzy-logic controllers to provide closed-loop control for manufacturing systems with constant demands. This methodology is illustrated by examples of manufacturing systems with different configurations, and the results are compared with the results obtained for manufacturing systems under crisp-logic control. Robust fuzzy-logic controllers are also developed for manufacturing systems with sets of different constant demands. The crisp-logic and fuzzy-logic control methodologies developed in this thesis are also used for the control of manufacturing systems producing prioritised multiple product- types. These evolutionary crisp-logic and fuzzy-logic control methodologies are finally applied to an industrial design example involving an actual semiconductor packaging assembly line, and the results thus obtained are found to be superior to those obtained in industrial practice. Three evolutionary algorithms, namely, genetic algorithms, non-adaptive evolution strategies, and adaptive evolution strategies, are used to optimise both crisp-logic and fuzzy-logic production-control systems in the various parts of this thesis, and their relative effectiveness is compared. It is concluded that, although adaptive evolution strategies do not always necessarily p
Download or read book Production Control in Practice written by Henny Van Ooijen and published by John Wiley & Sons. This book was released on 2024-05-09 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Production Control in Practice Practice-oriented coverage of production planning and control processes for goods and services, written for any industry Production Control in Practice explores the operational control of production and inventory processes in organizations across industries, covering both tangible and intangible products and offering viable, efficient solutions to characteristic production control problems, such as what goods to produce when and how. A number of examples/stylized applications are included to help readers understand and apply the discussed concepts and theories to their own organizations. This book distinguishes between the control of production units and the control of goods flow between these units and the market and discusses various coordination and material supply control mechanisms relevant to supply chains. It also presents a typology of production situations found in practice, using a structured approach to discussing the relevant control decisions for each situation. This book is unique because (basic) control decisions are discussed for the different characteristic Decoupling Point Control and Production Unit Control situations from a holistic point of view, taking into account both mathematical considerations as well as various situational factors. Sample topics covered in Production Control in Practice include: Terminology and concepts used in production control, including complexity, uncertainty, and flexibility Types of release triggers, covering just-in-time versus just-in-case and push versus pull in logistics Horizontal and vertical decomposition, and time series-related forecasting for stationary demand versus demand with trend Order size, covering optimal batch size in case of fixed order size, relaxation of assumptions, and single period considerations MRP systems, covering Material Requirements Planning (MRP-I) and Manufacturing Resource Planning Systems (MRP-II) With excellent coverage of the subject across different products and industries and several examples to help readers follow along, Production Control in Practice is an ideal reference for bachelor students from universities of applied sciences and academic bachelor students, as well as practitioners in related disciplines.
Download or read book Product Life Cycle Optimization Models for Closed Loop Supply Chains written by Aswin Dhamodharan and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Supply Chain Network design is an important strategic decision that helps Original Equipment Manufacturers (OEMs) to position their supply chains for profitable reverse supply chains. We observe that between the competitors of technology products, companies such as HP and Xerox (printers) and Apple and Google (smartphones), one competitor (HP and Apple) manages the reverse supply chain to extract value in a profitable manner, while the other competitor (Xerox and Google) uses a third-party reverse logistics company to simply recycle consumer returns. In the literature, supply chain levers, such as consumer Willingness to Pay (WTP) for remanufactured products, managing the collection process of consumer returns, the quality of the consumer returns and the design of reverse logistics have been identified as key factors influencing OEM participation in reverse supply chain. In this thesis, we show that, under the same supply chain levers mentioned above, the OEMs approach to supply chain network design can significantly impact the profitability in the reverse supply chain over the product lifecycle. To address the supply chain network design problem for an OEM, we propose an integrated multi-period optimization model called Product Life Cycle Optimization Model (PLCOM), to design the Closed Loop Supply Chain (CLSC) for the OEMs. The PLCOM is a Mixed Integer Linear Program that consists of a Demand model and a Pricing model. The Pricing model determines the optimal production quantity and the selling price computed over the product life cycle, based on a realistic customer Willingness to Pay (WTP) for new and remanufactured products. The Demand model computes the demand for new and remanufactured products based on the Extended-Basss diffusion model. The PLCOM also computes the cannibalization of new product sales due to the introduction of remanufactured product and the availability of product returns for remanufacturing, constrained by the collection of the returns. The Demand and Pricing models are then integrated into a Mixed Integer Program (MIP) model to design the CLSC network.The PLCOM is applied to a realistic case study using Apples iPhone 7 for a product life cycle of 8 years. The final MIP model has 30 binary variables, 48066 continuous variables and 3972 constraints and was solved using CPlex in 0.1619 seconds. We show that an integrated approach to design the supply chain network by the OEMs is more profitable compared to a sequential approach, where the OEM initially designs the optimal forward supply chain network and implements it. Later, when the OEM decides to participate in the remanufactured market, the OEM revisits the network design to obtain the optimal CLSC for the reverse supply chain. Using sensitivity analysis, we also show that slow diffusing products are more profitable for remanufacturing and fast diffusing products require flexibility in capacity planning, in order to avoid the fixed cost of opening additional facilities. In the case of fast diffusing products, we also observe a delayed surge in demand for remanufactured products caused by a delayed cannibalization effect on new product demand. Finally, a sensitivity analysis on the quality of the consumer returns gives an upper bound on the investment that can be made by the OEM in incentivizing the consumers to improve the quality of the returns.In the technology industry, frequent new product releases entail OEMs to concurrently manage successive generations of products. For example, Apple currently sells multigeneration iPhones, such as iPhone 6S, iPhone 7, iPhone 8 and iPhone X. Hence, we extend the integrated model to a two-generation product setting. We model the demand for the second-generation product as a substitution for the first-generation product. We identify the \textit{logit} function as the substitution function to compute demand for the second-generation product and validate total sales using the iPhone4 and iPhone 4S sales data. The extended PLCOM is again used in a realistic case study based on the consumer WTP for iPhone 7 and iPhone 8 as the successive generations of products. The extended PLCOM has 30 binary variables, 77474 continuous variables and 6470 constraints and the optimization problem was solved using CPlex and the solver took 46 seconds to solve the problem. Finally, we conduct a sensitivity analysis to determine the most profitable time to introduce the second-generation product, characterize the slow and the fast diffusing products in the two-generation product setting and analyze the impact of the quality of consumer returns on the profit.
Download or read book Handbook of Manufacturing Control written by Hermann Lödding and published by Springer Science & Business Media. This book was released on 2012-12-13 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unternehmen mit kurzen Lieferzeiten, hoher Liefertreue und niedrigen Beständen wachsen schnell und erzielen hohe Gewinne. Wie Unternehmen diese logistische Herausforderung meistern können, zeigt das Buch anhand von aktuellen Forschungsergebnissen der Leibniz Universität Hannover. Der Band gibt einen umfassenden Überblick über die Aufgaben und Verfahren der Fertigungssteuerung und befähigt Leser dazu, Schwächen in diesem Bereich zu erkennen und zu korrigieren. Ein fundiertes Nachschlagewerk für Studierende, Dozenten, Ingenieure und Wissenschaftler.
Download or read book Closed Loop Supply Chains written by Mark E. Ferguson and published by CRC Press. This book was released on 2010-04-21 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Closed-loop supply chain activities such as remanufacturing, recycling, dismantling for spare parts, and reverse logistics have helped many companies tap into new revenue streams by finding secondary markets for their products, all while reducing their overall carbon footprint. Written by academic experts, in language that is accessible to practitioners, this authoritative resource examines recent research and case studies of companies running profitable reuse/remanufacture operations in various industries. It illustrates profitable practices in returned and recovered products, clearly explaining how to: design a reverse logistics network, conduct production planning, implement effective marketing strategies, and apply closed-loop supply chain strategies in industries besides manufacturing. From product development to materials to assembly and profitability, this complete resource explores the impact of these processes across all aspects of the supply chain.
Download or read book Large Scale Optimization in Supply Chains and Smart Manufacturing written by Jesús M. Velásquez-Bermúdez and published by . This book was released on 2019 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, theory of large scale optimization is introduced with case studies of real-world problems and applications of structured mathematical modeling. The large scale optimization methods are represented by various theories such as Benders' decomposition, logic-based Benders' decomposition, Lagrangian relaxation, Dantzig -Wolfe decomposition, multi-tree decomposition, Van Roy' cross decomposition and parallel decomposition for mathematical programs such as mixed integer nonlinear programming and stochastic programming. Case studies of large scale optimization in supply chain management, smart manufacturing, and Industry 4.0 are investigated with efficient implementation for real-time solutions. The features of case studies cover a wide range of fields including the Internet of things, advanced transportation systems, energy management, supply chain networks, service systems, operations management, risk management, and financial and sales management. Instructors, graduate students, researchers, and practitioners, would benefit from this book finding the applicability of large scale optimization in asynchronous parallel optimization, real-time distributed network, and optimizing the knowledge-based expert system for convex and non-convex problems.
Download or read book Bulletin of the Atomic Scientists written by and published by . This book was released on 1961-05 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Bulletin of the Atomic Scientists is the premier public resource on scientific and technological developments that impact global security. Founded by Manhattan Project Scientists, the Bulletin's iconic "Doomsday Clock" stimulates solutions for a safer world.
Download or read book Queuing Models for Multi Product Pull Type Inventory Systems written by Kumar Satyam and published by LAP Lambert Academic Publishing. This book was released on 2011-07 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Competitive pressures are forcing manufacturing companies to find new ways to provide a wide variety of products at reduced costs. Pull type material control strategies that make efficient use of available production capacities and optimize inventories could be very useful in improving factory operations. However, there is aneed for analytical tools that precisely model the operating characteristics of multi-product pull systems. Such models should not only provide reasonably accurate performance estimates butalso be amenable to rapid analysis of performance tradeoffs. This book presents an analytical approach to solve multi-product systems with pull type material control strategies. A state of the art queuing theory based approach to solve analytical models for multi-product pull systems is being discussed. A parametric decomposition based approach is used to analyze multi-product pull systems under different settings such as batch size constraints, multi-stage production, finite demand and raw material. The approach presented in this book has been found to be reasonably accurate even in realistic settings.
Download or read book Handbook of Ripple Effects in the Supply Chain written by Dmitry Ivanov and published by Springer. This book was released on 2019-04-17 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers an introduction to the ripple effect in the supply chain for a broad audience comprising recent developments. The chapters of this handbook are written by leading experts in supply chain risk management and resilience. For the first time, the chapters present in their synergy a multiple-faceted view of the ripple effect in supply chains, while considering organization, optimization, and informatics perspectives. Ripple effect describes the impact of a disruption propagation on supply chain performance, structural designs and operational parameters. The ripple effect manifests when the impact of a disruption cannot be localized and cascades along the supply chain. The resulting structural dynamics can lead to capacity and demand fulfilment downscaling and negatively influence the firm’s financial and operational performance. The book delineates major features of the ripple effect and methodologies to mitigate the adverse impact of supply chain disruption propagation and to recover in case of severe disruptions. The book provides fresh insights for supply chain management and engineering regarding the following questions: - In what circumstance does one failure cause other failures? - Which structures of the supply chain are especially susceptible to the ripple effect? - What are the typical ripple effect scenarios and what are the most efficient ways to respond them? Distinctive Features: • It considers ripple effect in the supply chain from an multi-disciplinary perspective• It offers an introduction to ripple effect mitigation and recovery policies in the framework of disruption risk management in supply chains for a broad audience• It integrates management and engineering perspectives on disruption risk management in the supply chain• It presents innovative optimization and simulation models for real-life management problems• It considers examples from both industrial and service supply chains• It reveals decision-making recommendations for tackling disruption risks in the supply chain in proactive and reactive domains.
Download or read book Analysis of Delayed Product Differentiation Under Pull Type Policies written by Heedong Kim and published by . This book was released on 2002 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Delayed product differentiation (DPD) increases manufacturers' competitiveness in the market by enabling them to more quickly respond to changes in customers' demands. DPD has also been shown to require less Work-in-Process (WIP) than a non-DPD setup in some cases. Previous research was mainly focused on the level of semi-finished and/or finished good inventory under a base-stock policy. The control of WIP inventory was not considered. DPD may also improve response times under pull inventory control schemes, in which the amount of WIP is controlled directly. These systems can be modeled as closed queueing networks in which a fixed number of kanbans circulate as customers among each set of one or more processing stages. In this study, we first developed models to analyze the performance of simple kanban and CONstant-WIP (CONWIP) controlled systems and set the number of kanbans to achieve a specified performance level. The models help us better understand the behavior of pull systems. The performance evaluation method uses nonlinear programming (NLP) models to bound the throughput for fixed number of kanbans or minimize the number of kanbans necessary to achieve a specified throughput. The model shows how random supplies and demands prevent equilibrium from occurring in a single-stage kanbans system. We studied a model for a system of two products with unlimited supply and demand using three CONWIP loops to represent the common processes and the differentiated processes for each product. The same system after DPD has more common processes and fewer differentiated processes. The NLP model can determine numbers of kanbans for each loop to achieve specified throughput targets. Because the throughput bounds are not as tight as desired, we developed a heuristic algorithm that starts from the NLP solution and adjusts the kanbans using simulation to evaluate the performance. A comparison of the result of the heuristic algorithm for the systems with and without DPD indicates that DPD reduces the amount of WIP necessary to achieve a specified throughput. Furthermore, we show how models of systems with similar structure can be generalized.
Download or read book Production Planning and Control of Closed loop Supply Chains written by Karl Inderfurth and published by . This book was released on 2001 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optimization Using Common Part Strategies in Closed loop Supply Chains written by Marco Schulze and published by . This book was released on 2009 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
