18,097 research outputs found

    The extension and exploitation of the inventory and order based production control system archetype from 1982 to 2015

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    In 1994, through classic control theory, John, Naim and Towill developed the ‘Automatic Pipeline, Inventory and Order-based Production Control System’ (APIOBPCS) which extended the original IOBPCS archetype developed by Towill in 1982 ─ well-recognised as a base framework for a production planning and control system. Due to the prevalence of the two original models in the last three decades in the academic and industrial communities, this paper aims to systematically review how the IOBPCS archetypes have been adopted, exploited and adapted to study the dynamics of individual production planning and control systems and whole supply chains. Using various databases such as Scopus, Web of Science, Google Scholar (111 papers), we found that the IOBPCS archetypes have been studied regarding the a) modification of four inherent policies related to forecasting, inventory, lead-time and pipeline to create a ‘family’ of models, b) adoption of the IOBPCS ‘family’ to reduce supply chain dynamics, and in particular bullwhip, c) extension of the IOBPCS family to represent different supply chain scenarios such as order-book based production control and closed-loop processes. Simulation is the most popular method adopted by researchers and the number of works based on discrete time based methods is greater than those utilising continuous time approaches. Most studies are conceptual with limited practical applications described. Future research needs to focus on cost, flexibility and sustainability in the context of supply chain dynamics and, although there are a few existing studies, more analytical approaches are required to gain robust insights into the influence of nonlinear elements on supply chain behaviour. Also, empirical exploitation of the existing models is recommended

    Internal Supply-chain Competition In Remanufacturing: Operations Strategies, Performance And Environmental Effects

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    This paper investigates the competitive and environmental effects of different operations strategies of original equipment manufacturers (OEMs) and semi-independent remanufacturers, which simultaneously cooperate and compete in different stages of a closed-loop supply chain. In particular, a co-opetitive situation, in which remanufacturing is undertaken only by retailers while the OEMs' role is restricted to recycling is considered. After adopting a resource-based perspective of competition, investigations are accomplished using system dynamics simulation modelling. The results of simulations indicate that, in the long run, OEMs, regardless of the operation strategy they adopt, are unable to (re)capture the market gained by the remanufacturers. However, some of these strategies contribute to the improvement of the environmental performance of the entire supply chain

    Modelling the feedback effects of reconfiguring health services

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    The shift in the balance of health care, bringing services ‘closer to home’, is a well-established trend, which has been motivated by the desire to improve the provision of services. However, these efforts may be undermined by the improvements in access stimulating demand. Existing analyses of this trend have been limited to isolated parts of the system with calls to control demand with stricter clinical guidelines or to meet demand with capacity increases. By failing to appreciate the underlying feedback mechanisms, these interventions may only have a limited effect. We demonstrate the contribution offered by system dynamics modelling by presenting a study of two cases of the shift in cardiac catheterization services in the UK. We hypothesize the effects of the shifts in services and produce model output that is not inconsistent with real world data. Our model encompasses several mechanisms by which demand is stimulated. We use the model to clarify the roles for stricter clinical guidelines and capacity increases, and to demonstrate the potential benefits of changing the goals that drive activity

    Applying Revenue Management to the Reverse Supply Chain

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    We study the disposition decision for product returns in a closed-loop supply chain. Motivated by the asset recovery process at IBM, we consider two disposition alternatives. Returns may be either refurbished for reselling or dismantled for spare parts. Reselling a refurbished unit typically yields higher unit margins. However, demand is uncertain. A common policy in many firms is to rank disposition alternatives by unit margins. We show that a revenue management approach to the disposition decision which explicitly incorporates demand uncertainty can increase profits significantly. We discuss analogies between the disposition problem and the classical airline revenue management problem. We then develop single period and multi-period stochastic optimization models for the disposition problem. Analyzing these models, we show that the optimal allocation balances expected marginal profits across the disposition alternatives. A detailed numerical study reveals that a revenue management approach to the disposition problem significantly outperforms the current practice of focusing exclusively on high-margin options, and we identify conditions under which this improvement is the highest. We also show that the value recovered from the returned products critically depends on the coordination between forward and reverse supply chain decisions.remanufacturing;revenue management;onderdelen;revenues;spare parts inventory

    Modeling Alternatives Sustainable-Energy-Policy for the Supply Chain of Wind Power in Brazil.

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    Renewable energy studies have received high attention in the last few years due the increasing deployment of alternatives such as wind, solar and biomass, as a result of the urgency in reducing fossil fuels consumption. This situation has involved an important challenge for long-term renewables policy and energy system planning. Brazil is the richest country in terms of renewable sources in Latin American. Brazil has energy generation portfolio not much different form the Colombia one, and the understanding of this very important country will contribute to inspire other countries in the region, particularly Colombia. Since 2004 the Brazilian energy policy promotes wind power development aimed at complementing hydropower generation. Despite the energy policies adopted in Brazil, the supply chain of wind power has experienced barriers that include: insufficient transmission lines and the delays in energy projects caused by lack synchronic among the energy policies. Thus, the unsynchronised energy policy has affected the performance of renewable energy supply chain, which has produced an impact on the electricity market. This thesis addresses these issues by evaluating alternative sustainable energy-policy, which must reflect new institutional guidelines to support wind power penetration and their dynamics performance in supply chain

    Sustainability in China: Bridging Global Knowledge with Local Action

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    China’s road to sustainability has attracted global attention. Since the “Reform & Opening Up” policy, China’s rapid pace of both urbanization and industrialization has made its being the second largest economy but meantime a heavy environmental price has been paid over the past few decades for addressing the economic developmental target. Today, as the biggest developing country, China needs to take more responsibilities for constructing its local ecological-civilization society as well as for addressing the global challenges such as climate change, resources scary and human beings well-fare; therefore, we need to have deeper understandings into China’s way to sustainability at very different levels, both spatially and structurally, concerns ranging from generating sustainable household livelihoods to global climate change, from developing technological applications to generate institutional changes. In this spirit, this publication, “Sustainability in China: Bridging Global Knowledge with Local Action” aims to investigate the intended and spontaneous issues concerning China’s road to sustainability in a combined top-down and bottom-up manner, linking international knowledge to local-based studies

    Inventory control systems model for strategic capacity acquisition

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    Variation of installed industrial capacity has been found to follow a cyclic pattern. This paper discusses the application of control theory to the problem of the timely acquisition of extra production capacity. The control system based model presented here is compared with a System Dynamics model proposed by Sterman. Key differences are the method of implementing rational decisions about deployment of extra capacity and the use of a nonlinear APVIOBPCS inventory model. Benefits of this new model are a more measurable process and the ability to select parameter values to optimise capacity deployment. Simulation of the model indicates that the results found by Sterman underestimate the production backlog and time taken to reach equilibrium. The use of a Proportional, Integral, and Derivative (PID) controller in the capacity control loop model illustrates that it is possible not only to alter the backlog levels but at the same time to reduce the sales force and improve the revenue. The model also shows clearly that the impact of not increasing capacity promptly results in catastrophic failure of sales as a structural, rather than a business, problem. This model is simple enough to be implemented as a spreadsheet for use as a guide by managers

    Inventory control systems model for strategic capacity acquisition

    Get PDF
    Variation of installed industrial capacity has been found to follow a cyclic pattern. This paper discusses the application of control theory to the problem of the timely acquisition of extra production capacity. The control system based model presented here is compared with a System Dynamics model proposed by Sterman. Key differences are the method of implementing rational decisions about deployment of extra capacity and the use of a nonlinear APVIOBPCS inventory model. Benefits of this new model are a more measurable process and the ability to select parameter values to optimise capacity deployment. Simulation of the model indicates that the results found by Sterman underestimate the production backlog and time taken to reach equilibrium. The use of a Proportional, Integral, and Derivative (PID) controller in the capacity control loop model illustrates that it is possible not only to alter the backlog levels but at the same time to reduce the sales force and improve the revenue. The model also shows clearly that the impact of not increasing capacity promptly results in catastrophic failure of sales as a structural, rather than a business, problem. This model is simple enough to be implemented as a spreadsheet for use as a guide by managers
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