Modularization in material flow simulation for managing production releases in remanufacturing

Jnl Remanufactur (2017) 7:139–157 DOI 10.1007/s13243-017-0037-3 RESEARCH Modularization in material flow simulation for managing production releases in remanufacturing Lorenzo Gaspari 1 & Lorenzo Colucci 1 & Steffen Butzer 2 & Marcello Colledani 1 & Rolf Steinhilper 2 Received: 10 April 2017 / Accepted: 21 July 2017 / Published online: 4 October 2017 # Springer Science+Business Media B.V. 2017 Abstract Remanufacturing is recognized as a major circular economy option to recover and upgrade functions from post-use products. However, the inefficiencies associated with operations, mainly due to the uncertainty and variability of material flows and product conditions, undermine the growth of remanufacturing. With the objective of supporting the design and management of more proficient and robust remanufacturing processes, this paper proposes a generic and reconfigurable simulation model of remanufacturing systems. The developed model relies upon a modular framework that enables the user to handle multiple process settings and production control policies, among which token-based policies. Customizable to the characteristics of the process under analysis, this model can support logistics performance evaluation of different production control policies, thus enabling the selection of the optimal policy in specific business contexts. The proposed model is applied to a real remanufacturing environment in order to validate and demonstrate its applicability and benefits in the industrial settings. Keywords Remanufacturing . Kanban . Modularity . Simulation . Production control policies Introduction, motivation and objectives The increasing world population is leading to an upward momentum for resources demand, in order to satisfy emerging consumer requirements in the global market. However, this macrotrend poses a challenge on the need to decouple resource consumption and production to support a sustainable development. In this context, Circular Economy has been recently * Lorenzo Gaspari 1 Politecnico di Milano, Mechanical Engineering Department, via La Masa 1, 20156 Milan, Italy 2 Chair Manufacturing and Remanufacturing Technology, Universität Bayreuth, c/o LUP, Universitätsstraße 9, 95447 Bayreuth, Germany 140 Jnl Remanufactur (2017) 7:139–157 proposed as a new paradigm for sustainable development, showing potentials to generate new business opportunities in worldwide economies, to increase a long-term competitive advantage [1] and to significantly increment resource efficiency in manufacturing. The application of closed-loop business models may enable to exploit materials potentials within multiple cycles, reducing emissions, energy requirement and resource consumption, ultimately preserving the welfare of next generations. Focusing on the operational perspective of circular economy, remanufacturing is acknowledged among the most beneficial end-of-life product regeneration strategies. Indeed, it provides the possibility of preserving post-use products or components functions, regenerating them to their as-good-as-new conditions [2]. Although remanufacturing is gaining interest due to its profitability and environmental benefits, the related instability, uncertainties and complexity [3], particularly at an operational level, undermines its growth. With the objective of providing increased robustness to remanufacturing processes while limiting inventory levels, this work proposes an innovative simulation framework for predicting the performance of remanufacturing systems operating under various production control policies within a digital environment, before the implementation in the real system. The proposed tool provides remanufacturing business stakeholders with an effective solution which supports the management of remanufacturing systems under evolving production targets, thus lowering the exposition of companies to input disturbances and uncertainties. Such objectives are pursued through the proposition of a generic and reconfigurable simulation model, which exploits a modular approach. The characteristics of each process module are customized in order to capture the features of typical remanufacturing processes, including disassembly, inspection, cleaning, regeneration, functional testing and re-assembly. Moreover, in the proposed simulation environment, the ability to compose different remanufacturing system architectures is provided, while maintaining an adequate level of detail to capture the main dynamics characterizing the system’s behaviour. The model is also enriched with the capability of handling different production control policies. The ultimate aim of this work is to support the design, reconfiguration and management of robust remanufacturing systems, adaptable to variable production targets and input post-use product flows and conditions. The remainder of this paper is structured as follows. In the next section, a literature review on remanufacturing planning and control methods is provided, also highlighting the existing gaps and limitations. In section 3, the scientific approach proposed in this paper is outlined and the detailed description of the simulation model is proposed. Numerical validations through comparison with existing performance evaluation methods, targeted to a sub-set of low complexity system configurations, are also provided. In section 4, the application to a real remanufacturing industrial case is demonstrated, and potential benefits are discussed. In section 5, the main conclusions are drawn. Literature review Since decades, simulation is a well-known approach for business forecasts and development, mainly applied to the manufacturing domain. In-spite of the complexity of remanufacturing and the related uncertainties and disturbances, relatively little effort has been devoted to the application of simulation in remanufacturing systems. Despite the presence of studies rooted in the nineties [4] [5], simulation has always faced limitations in remanufacturing applications. The main reason is that the proposed simulation models Jnl Remanufactur (2017) 7:139–157 141 were circumscribed to specific, case-dependent assumptions, which imply difficulties in the adaptation and generalization of the presented solutions over different remanufacturing scenarios. Among these works, Souza and Ketzenberg modelled the operations occurring in remanufacturing activities [6] and focused their efforts on determining the optimal longrun product mix, maximizing profit subject to a service time constraint [7]. Moreover, Zhang, Ong and Nee tackled the problem of process planning and scheduling through the application of a simulation-based framework, optimized by a genetic algorithm [8]. The concept of modularity has been largely deployed in the field of manufacturing, both at product and production system design level, and its application provided significant benefits in terms of manufacturing costs and lead times [9] [10]. In material flow si (...truncated)