A remanufacturing process library for environmental impact simulations

Nurul Hanna Ismail Guillaume Mandil Peggy Zwolinski 'Closed loop' end-of-life strategies such as remanufacturing must be applied to create eco-efficient products. Remanufacturing may be a key element in reducing the environmental impact of products, but this remains to be proved. The aim of this study is to help designers evaluate the environmental impacts of their remanufacturing process during the design phase. The first task is to identify, list and classify the various remanufacturing processes (disassembly, cleaning, sorting and controlling, reconditioning, reassembly) by the type of process and then estimate the environmental impact for each process. These processes are then formalized by characterization and organized in a database. Using a simulator, the different processes can be aggregated to assess the environmental impacts of a remanufacturing line. An example is presented in the last part of this paper to illustrate the proposal. - Figure 1 Closed-loop end-of-life product life cycle [23]. product shape [1]. This destroys most of the product's added value [3] and may represent a significant environmental impact [4]. Remanufacturing is defined as A process that brings a used product back to a new state through reuse, refurbishment and replacement of its components [5]. It is a process of disassembling, cleaning, inspection and sorting, reconditioning or replacing parts (if applicable) and reassembling a used product in order to make it at least as good as, or better, than a brand new one. By applying the remanufacturing process, a product can be returned to service with a reasonably high degree of confidence that it will at least endure another full life cycle. The main purpose of remanufacturing is to prolong the product life cycle and at the same time preserve the added value of the material during the design and manufacturing phases. From the environmental point of view, remanufacturing ensures sustainable products that save energy and material resources. Remanufacturing also diverts material from landfills and creates jobs for skilled workers [6]. The decision to integrate the product remanufacturing process must be made at the earliest stages of the product life cycle [7,8] to ensure the outcome is successful. To better understand this field, Lund [9] defined three different types of remanufacturing company. The first type is the Original Equipment Manufacturer (OEM) which remanufactures its own products. The second type is the Subcontractor Company which remanufactures products made by other companies (usually the OEMs). The last type is the Independent Remanufacturer (IR) which remanufactures products without much contact with the OEMs. They also have to buy or collect the core components for their process. Many studies have confirmed that remanufacturing is more profitable for OEMs [10,11]. Several studies have focused on proving the environmental benefits of remanufacturing. These studies include that of Kerr et al. [12] on the eco-efficiency gains derived from remanufacturing, based on a study of Xerox photocopiers in Australia. It attempted to quantify the overall life cycle environmental benefits of remanufacturing by comparing the remanufacturing of a traditionally designed photocopier and a photocopier designed to facilitate its own remanufacturing. In addition, Lindahl et al. [13] identified the general environmental advantages and disadvantages of remanufacturing by modelling a life cycle assessment of several households' appliances and products. An environmental comparison was performed of end-of-life scenarios (remanufacturing and recycling) for all of these appliances and products. Likewise with J. Amaya, who carried out a comparative assessment of remanufactured product life-cycles and classical life-cycle scenarios. This approach was illustrated by a case study of a truck injector [14]. Even though there have been many difficulties in defining and interpreting the system's boundaries, the measurement methods used and the result itself, this research has come to the conclusion that remanufacturing is a preferable option in comparison to new manufacturing and other end-of-life options [15]. Despite these advantages, remanufacturing lacks a tool for modelling the environmental impact of its process. Tools such as Remanufacturing Decision-Making Framework (RDMF) have been developed by researchers to promote remanufacturing in companies. It is a decision-making framework which helps management to make decisions on whether or not to remanufacture a product [7,8]. REPRO2 [16] is a tool that allows designers to monitor the evolution of design parameters for remanufacturing [1]. The CLOEE tool [17] has been developed at the G-SCOP laboratory. This tool is designed to assess the environmental impact of multiple end-of-life scenarios. It is particularly useful when many end-of-life strategies with different options have to be tested. However, CLOEE requires a certain quantity of environmental impact data as inputs in order to test each process or scenario. These data could be obtained using the remanufacturing process library proposed in this paper. Nowadays, there are evermore methods and technologies that complete each remanufacturing phase. This phenomenon is positive for remanufacturers because they have a large variety of options available for setting up the remanufacturing system. Moreover, current technologies allow the remanufacturing of products that could not be remanufactured before. But having more choices leads to more confusion for designers when they are not equipped with the tools they need to highlight the environmental impacts of their process. The absence of this kind of tool always leads designers to ask about the basic rules for choosing a method/technology capable of minimizing environmental impacts. The global impact of remanufacturing on the environment is also one of the aspects that still remain uncertain. All these issues show the importance of having tools to help designers answer these questions. From the environmental standpoint, it is difficult to optimize the remanufacturing process without knowing its impacts on the environment for the entire product life cycle. Data from studies of existing remanufacturing systems have been limited and patchy [12]. Because of these problems, it is reasonable to propose a database and a tool intended to help remanufacturers and designers to evaluate and compare the environmental impacts of their remanufacturing process during the design phase. This study is aimed at helping remanufacturers and designers to compare environmental impacts and make decisions. In this article, a global representation of the remanufacturing process is presented. This is followed by a detailed explanation of the construction of the remanufacturing process library, the calculation of the environmental parameters, and the creation of the environmental impact simulator. In the last part, the sim (...truncated)