Remanufacturing Process Research Articles

Reverse Logistics Modeling Considering Environmental and Manufacturing Costs: A Case Study of Battery Recycling in Indonesia

This article models a reverse logistics network for battery recycling with consideration of environmental and manufacturing costs. The model is developed for a reverse flow multi-echelon supply chain, from end customers to the remanufacturing process. Linear programming is used to formulate mathematical models and LINGO® is applied to solve the problem of determining optimal orders for and sales of recycled batteries, lead alloy and plastics, as well as the optimal level of safety stock (service level) for the recycling centers along the reverse logistics network. The number of battery orders from unused battery collectors, and the sales of lead alloy and plastics to the remanufacturing process considering transportation, environmental cost, disassembly cost and inventory costs, are found optimally in different periods. The study also indicates that there is a correlation between the associated costs and inventory decisions and total profit in recycling centers.

The strategy for implementing remanufacturing process in a commercial enterprise, the case study of a French company

Remanufacturing is considered one of the most effective and efficient end-of-life strategies of the circular economy, in terms of environmental benefits and economic viability. Products are circulating all over the world, coming from multiple sources and numerous intermediates. Thereby, making the supply chain between the user and the Original Equipment Manufacturer (OEM) very complex when it comes to recovering products at their end-of-life. In fact, local sellers have direct contact with users, as they are geographically close, which makes it easier for them to recuperate worn out and obsolete products. However, these sellers lack the know-how and the technical knowledge necessary to develop the remanufacturing process. This paper presents the strategy to be followed by small companies to adopt and implement the remanufacturing process, in order to give these end-of-life products a second life and to make a profit from both new and remanufactured products. In particular, it focuses on the specific case of a small company in France, that included the process of remanufacturing air compressors and electric motors in its business model and started selling them directly to users. Therefore, this study will display the multiple advantages that this remanufacturing strategy has to offer and will also show the barriers that can be faced when applying this strategy.

A partially backlogged supply chain model for deteriorating items under reverse logistics, imperfect production/remanufacturing and inflation

Reverse logistics increasingly conquered interest in the past decade. It consists of operations related to the reuse of products, such as the collection of products from end users and general processes such as reusing, repairing, and recycling. In this paper, a reverse logistics supply chain inventory model in an inflationary environment is developed. Production and remanufacturing rates are finite and variable. During the production (remanufacturing) process some imperfect quality products are produced (remanufactured), which are reworked after production (remanufacturing) run. Items deteriorate over time with time-varying deterioration rate. Many classical reverse logistics supply chain models are developed with constant demand rate and ignoring the shortages which are not true all the time in practical life. Therefore, in this model, it is assumed that the demand rate of the buyer is a function of on-hand inventory and selling price. Shortages are allowed only for the buyer and partially backordered with a time-dependent backlogging rate. The purpose of this study is to determine the optimal integrated reverse logistics supply chain policy. Finally, numerical examples and sensitivity analysis along with some decision-making implications are provided.

A novel approach for developing a flexible automation system for rewinding an induction motor stator using robotic arm

Abstract Electric motor rewinding is a traditional restorative and regenerative process, which is lagging in adopting new and current market trends. Stator rewinding is a crucial task in electric machine manufacturing and is the most challenging operation. This has raised the need to automate the system. In this light, this paper aims to develop a concept for developing a flexible automation system for rewinding an induction motor stator using a robot arm. To achieve this, a bottom-up approach and model predictive control (MPC) has been utilized in the design due to manufacturers’ specification disparities. The results reveal that the system can be trained successfully, to perform the remanufacturing process 6 times faster than the manual process. The system also allows for data mining. Successful application of this approach will demonstrate the importance of using flexible automated systems for induction motor stator rewinding and reduce time and winding steps.

Analysis of Factors Causing Delays in the Diesel Engine Remanufacturing Process at an Indonesian Company

HeavyEq is an Indonesian company that remanufactures diesel engines for the mining industry. The company experiences delays in the remanufacturing process that lead to a sales backlog. The main purpose of this paper is to identify the root cause of, and propose a solution to, the problem. A fishbone diagram is developed to identify the root cause, and the results show that delays in the remanufacturing process are mainly caused by uncertainty over cores (used engines) in terms of their arrival time, quantity, and quality. Based on a literature review and interviews with experts, an improvement in core acquisition activity, separating job orders for disassembly and recovery, and reassembly processes is proposed to reduce delays in the remanufacturing process.

A data-driven simulation to support remanufacturing operations

Simulations are a vital component in developing smart manufacturing systems, predicting the behaviour of the manufacturing shop floor operations to support production planning, scheduling and maintenance decisions within manufacturing environments. However, simulations are often limited in their ability to support real-time business decisions in complex fast changing environments due to the cost and time required to build, update and maintain simulation models. Remanufacturing operations in particular could benefit from the use of simulations as a tool to support the assessment of different strategies to real-time scenarios due to the uncertain nature of product returns.This research develops a data-driven simulation approach to predict material flow behaviour within remanufacturing operations, by utilising data from digital manufacturing systems (i.e. databases, traceability systems, process plans) to update and automatically modify the simulation constructs to reflect the real world or planned system. A data-driven simulation is proposed comprising of three elements: (i) an adaptive remanufacturing simulation algorithm to model the complex material flow found within a remanufacturing process in a generic and reusable way, (ii) a remanufacturing information model to structure and highlight the simulation data requirements and (iii) an information service layer to collect and analyse sensor data for use within the simulation. The simulation is implemented to demonstrate how it can automatically reconfigure and adapt to changes within the data inputs (process and factory models) using a case study of operations from a Waste Electrical and Electronic Equipment (WEEE) remanufacturer, utilising data collected from a Radio Frequency Identification (RFID) traceability system installed within the remanufacturing facility.

Research on Laser Additive and Milling Subtractive Composite Remanufacturing Process of Compressor Blade

As an important energy conversion mechanism, centrifugal compressors play an important role in the national economy. The blade is one of the most critical components of the compressor. Damaged blades contain extremely high added value for remanufacturing. Thus, remanufacturing research on damaged and retired impeller/blade is getting more and more attention. Laser additive and milling subtractive composite remanufacturing technology is an effective means to achieve metal parts remanufacturing. In this paper, an advanced methodology for the remanufacturing of complex geometry and expensive components via reverse engineering, free-form surface modeling, laser additive repaired and machining is presented. The approach involves the integration of 3D non-contact digitization to obtain the point cloud data of damaged parts, adaptive free-form surface reconstruction to get the digital model of damage location, and laser additive manufacturing process containing slicing and path planning and subsequent multi-axis milling operation. The methodology has been successfully implemented on thin-curved centrifugal compressor blades. The results have shown that the composite remanufacturing method is an effective solution to realize the remanufacturing of damaged blades, and can be applied to the remanufacturing of other complicated parts.

Multi-variable optimisation of the quality characteristics of fiber-laser cladded Inconel-625 composite coatings

Inappropriate choice of processing and materials parameters when re-manufacturing industrial equipment, via laser cladding (LC) technique, has adverse implications for attaining durability of equipment in terms of functional performance, efficient lead time and cost savings for equipment repairers. In an attempt to promote the adoption of LC as an efficient equipment re-manufacturing process, this study employs central composite design (CCD) and response surface modeling (RSM) to build mathematical models for optimising the quality characteristics (dilution ratio and microhardness and LC process efficiency) of a composite coating. The quality characteristics of the coating, comprising of Inconel 625 matrix reinforced with tungsten carbide (WC) particles, were optimised as functions of laser energy density, inconel content in the composite coating and shielding gas flow rates. Evidence from this study establishes that laser energy density is the dominant factor which influences all the output responses. It was also revealed that predicted values of the quality characteristics agree with the experimental results within the permissible range of the LC process and materials variables. Consequently, dilution ratio was minimised as coating's microhardness and process efficiency were maximised with appropriate combination of laser energy density, inconel content and shielding gas flow rates. Finally, it may be inferred from this analysis that quality characteristics are optimised at 67.6 wt% inconel content, laser energy density (18.60 J/mm2) and career/shielding gas flow rates (8.86 l/min) with desirability value of 1.00.

Determination of Criticality Indexes in the Remanufacturing Process: A GERT-based Simulation Approach

In this paper one of the important “end of life options” (remanufacturing) has been analysed. Among the related studies surveyed the various remanufacturing aspects, less attention has been paid to the stochastic process routing. In this regard, a remanufacturing process routing with stochastic activities is modelled as a GERT network. One of the efficient ways to analyse a remanufacturing process is the identification of most effective activities based on the cost and time of the process during the process implementation. Criticality indexes are suitable scales for this purpose. Therefore, to analyse the important aspects of the remanufacturing process, four criticality indexes are developed in this paper. These indexes measure the cost and time of the process and its activities to identify the activities with high importance in terms of cost and time. On the other hand, simulation is an efficient tool to cope with the uncertainties in the production problems. Hence a Monte Carlo approach (which is developed using Arena software) has been adopted to analyse the GERT based model and to calculate the criticality indexes. In addition, a mathematical approach using Moment Generation Functions has been adopted to calculate the expected value of the criticality indexes. In addition, a numerical example (lathe spindle remanufacturing) has been solved using both proposed approaches. Results show the acceptable performance of the proposed GERT based simulation approach.

After-Sale Data Based Common Rail Injector Remanufacturability Analysis

The injector is the most critical and vulnerable part of a diesel engine, and injector remanufacturing seems to be a solution to change the adverse market conditions. For remanufactured injector, there are some differences between China and developed countries. These differences make a different remanufacturability. New remanufacturing process should be evaluated to determine the feasibility. Fuqiang Power Company’s experiment and the survey from Bosch Diesel Centers (BDCs) show the status of the used injectors that nearly one-third of the used injector can be remanufactured with low cost. It is feasible to produce quality remanufactured injector under given process. Promoting clean diesel engine is more likely to be accepted by the consumer.

ANALYSIS OF THE DYNAMICS OF CHANGING THE INDICATORS OF THE FUNCTIONAL OCCLUSION ASSESSMENT METHOD T-SCAN IN PATIENTS WITH OCCLUSION DISORDERS WHICH HAVE BEEN ARISEN OR WERE ACTIVATED AS A RESULT OF INCORRECT DENTAL SURGERY

Recent studies showed that regaining the occlusal contacts is one of the most difficult tasks during the prosthetics remanufacturing process. It often happens, that during prosthetics remanufacturing process misunderstanding between a patient and a doctor may occur. It is related to the removal of expensive structures and manufacturing of new ones that are just as pricey. Thus, the touchstone for achieving optimal functional and esthetic results is not only the repositioning of the mandible that eliminates pain sensation in TMJ, but also regaining of the occlusal contacts is needed for prosthetics remanufacturing. Thereby, by knowing the treatment outcome, the doctor is able to minimize the risk of error in prosthetics re-manufacturing process and improve the doctor-patient relationship.Key words: maxillo-dental apparatus, temporomandibular joint, occlusive correction, masticatory muscles, pharmaceutical constructions

Surface remanufacturing of ductile cast iron by laser cladding Ni-Cu alloy coatings

Ductile cast iron is hard to be remanufactured without preheating and post heat treatment owing to the complicated phase evolution and a great tendency to form chilled structure during cladding process. Ni-Cu alloy shows great ability to obstruct the diffusion of carbon in the transition zone during the welding of cast iron due to the low solubility of carbon in nickel alloy. In the present study, different kinds of simulated grooves were devised to estimate the remanufacturing process of ductile cast iron by laser cladding. Ni-Cu alloy were used as the filling material. The microstructure and phase evolution in the transition zone were illustrated and mechanical properties have also been studied. Scanning electron microscopy (SEM), energy dispersive microanalysis (EDS), X-ray diffraction (XRD) and transmission electron microscope (TEM) were used to identify the microstructure and phase types of the claddings and transition regions. The result illustrated that various microstructures were formed during laser remanufacturing. Circular groove and cross cladding procedure were conductive to reduce residual stress. Microhardness decreased obviously after multi thermal cycles. The specimen shows ultimate strength of 502 MPa no less than that of the substrate.

Price optimization of multi-stage remanufacturing in a closed loop supply chain

Abstract In a remanufacturing process within the closed loop supply chain (CLSC) the manufacturers collect the end of life or used products from the customers and repair/refurbish them to sell it along with newly manufactured products. This phenomenon is common for products which are mechanical in nature and contains more reuse value. The reverse supply chain part of acquiring the used products incurs acquisition cost and remanufacturing cost, which depends on the quality or grade of returned product. Generally, the remanufacturers pay higher acquisition prices for good quality returned products and lower acquisition prices for poor quality returned products. Also, the remanufacturing cost is a decreasing function of the quality of the returned products. But if the returned product can be refurbished and remanufactured in the corresponding stage of supply chain, it can be sold along with newly manufactured product. Inclusion of remanufactured products will reduce the demand of raw materials or sub components required from suppliers. This reduction in this cost may be transferred in the form of price of the product charged to the customer in forward supply chain. With this backdrop, a non-linear unconstrained model is proposed with the objective of maximizing closed-loop supply chain (including remanufactured products) profitability considering a price dependent demand. The decision variables to be determined are sale price, acquisition prices for stages, total return percentage to be accepted and their distribution. Some interesting insights can be drawn to analyse whether there will be price difference in CLSC arrangements compared to only forward supply chain without considering remanufactured products. A numerical example along with sensitivity analyses at the end gives the insights regarding circumstances under which CLSC operation is really profitable vis-a-vis FSC operation only.

Opportunities and incentives for Remanufacturing in the Basque Country

Remanufacturing is a business model that helps the development of the circular economy. There are numerous successful examples of remanufactured products in different industrial sectors of Europe and US. Obtaining the maximum benefit of remanufacturing is related to the client recognizing the value of his assets at the end of its life, and that the manufacturer makes products that have the functionality and durability required. These aspects, can be improved if the remanufactured products are converted into a product-service systems (PSS). The objective of this research is to identify the opportunities, challenges, drivers and barriers for the development of remanufacturing activities in the main industrial sectors of the Basque Country. The research team has analysed 890 industrial companies, of which 197 companies have been identified the potential to development their remanufacturing process. After that, in order to know the reality of the different industrial sectors of the Basque Country, the research team developed a questionnaire oriented to the companies with the highest remanufacturing potential. In addition, they interviewed the industrial managers and directors of innovation of the 18 leading industrial companies in the Basque Country. The research team estimated that the remanufacturing process in the Basque Country is an emerging activity with great potential for development for 2025. The initial sales estimate for the five priority sectors analysed in 2016 is 63.6 million euros, and for 2025 is 163 million. According to the interviews, the main motivations that companies have for remanufacturing are strategic advantage and differentiation, high product value and high durability of the product. The main barriers identified are access to products, the resulting quality and market valuation.

DEMATEL approach for analyzing the critical factors in remanufacturing process

Sharp rise in end of life products and depletion of natural resources stimulate the need of remanufacturing of automotive, electrical and electronics products globally. But developing countries are still facing challenges in successful adoption of remanufacturing practices.This paper attempts to identify and analyze the key issues which may influence the remanufacturing process. Twelve critical factors are determined after thorough literature review and DEMATEL technique is used to develop causal relationship among the factors. The results of this research reveal that government regulations and incentives, consumer acceptance and return tendency are significant factors which has strongest driving power for remanufacturing activities.Moreover, perceived benefits and production planning and control factors are found to be influenced strongly by other factors.

A Technical Assessment of Product/Component Re-manufacturability for Additive Remanufacturing

Products/Components received after being used are of a significant uncertainty and variability when it comes to their quantity and quality levels. A technology with a flexible production, in terms of free processing, able to cope with the challenges of uncertainty in remanufacturing processes is needed. By adding material layer by layer, additive manufacturing (AM) represents a new technology that might have a positive impact on the circular economy strategies. Previous studies reviewed the implications of additive remanufacturing from its technical feasibility and the sustainable viability of such processes. These works did not take into account the characterization and selection of Products/Components able to be remanufactured by additive remanufacturing process. This work will focus on the products/components with characteristics that are adequate with additive remanufacturing. It will also present a framework of additive remanufacturing and the key steps in order to allow the remanufacturer to decide on the re-manufacturability of the products using additive manufacturing technologies. This assessment feedback might improve the design and the manufacturing processes for additive remanufacturing.

Adaptive geometry transformation and repair for hybrid manufacturing

In recent years, hybrid manufacturing has transitioned from research and development to commercially available industrial machine tools. This proliferation has led to a growing interest in the unique capabilities of these machines. Manufacturers in the mold and die, oil and gas, and aerospace industries are investigating hybrid manufacturing as a means of repairing high value components to reduce operating costs. As these parts become worn or damaged and taken out of service, each has its own unique distorted and worn geometry, and requires a distinct repair plan. This requires the repair strategy for these components to adapt to these fluctuations in geometry by modifying the re-manufacturing process on a part by part basis. This paper details a method of model transformation for adaptive part repair for use in a commercial hybrid manufacturing system. Nominal CAD geometry of the component is transformed based on data captured from the actual part geometry in a two-step process. The nominal geometry is first rigidly registered to the measured part data using an iterative algorithm. Then, individual cross sections of the nominal model are then deformed to match the actual data. After this transformation, final profile geometry can be constructed by using these informed transformations. This overall hybrid repair framework is shown to be of high accuracy and capable of yielding significant improvements in material usage efficiency and processing time compared to conventional repair approaches.

Integrated Workstation Design and Buffer Allocation in Disassembly Systems for Remanufacturing

Remanufacturing is recognized as one of the most profitable and environmentally conscious options of the circular economy. A remanufacturing process chain includes disassembly, cleaning, inspection, reconditioning and reassembly stages to recover the functionality and value of post-use products. However, the efficiency and profitability of remanufacturing are significantly affected by the variability of post-use product conditions. Consequently, the disassembly tasks times are highly uncertain, and this leads to a lack of robustness in disassembly lines designed without considering these challenges. This paper aims at finding the optimal disassembly line design under uncertainty of tasks times to support remanu-facturing. A mathematical optimization model with the objective of profit maximization is proposed which jointly optimizes and determines (1) the sequence of components to be disassembled and the assignment of disassembly tasks to workstations and (2) the allocation of buffers in order to provide a disassembly line design which has the maximum profit and satisfies the desired cycle time. The benefits of the proposed model are validated within a real case study dedicated to the remanufacturing of mechatronic components in the automotive industry.

Remanufacturing challenges and possible lean improvements

Remanufacturing is a viable way to prolong the useful life of an end-of-use product or its parts. Despite its economic, environmental, and social benefits, remanufacturing is associated with many challenges related to core (used product or its part) availability, timing and quality. The aim of this paper is to study how lean production could be used to tackle remanufacturing process challenges and contribute to shorter lead times. To meet this aim, we conducted a literature review and case studies of four remanufacturing companies. The case companies’ remanufacturing challenges were: (1) a lack of material requirements planning system, (2) poor core information, (3) a lack of core material, (4) poor spare parts information, (5) a lack of spare parts material, (6) insufficient quality management practices, (7) large inventories, (8) stochastic remanufacturing processes, (9) a lack of supply-demand balance, and (10) insufficient automation. These challenges contribute to long and variable remanufacturing process lead times. To tackle remanufacturing challenges, seven lean-based improvements with a major effect on improvements in lead time were suggested: standard operations, continuous flow, Kanban, teamwork, employee cross-training, layout for continuous flow, and supplier partnership. Providing that the suggested improvements are implemented, a possible lead time reduction of 83–99 per cent was projected.

Investment Strategy in a Closed Loop Supply Chain: The Case of a Market with Competition between Two Retailers

To survive in the ceaseless cycle of competition, businesses have developed strategies to become sustainable. These strategies include reusing products, which can lead not only to the creation of economic benefits but also to improvements in a corporation’s social and environmental responsibility. Product reuse can also increase the profit earned on new products by compensating customers who bring in old products to buy new ones, as the ensuing remanufacturing process allows for the reuse of materials and thus drives down costs. As businesses have come to recognize these values, the marketing competition to retrieve used products from customers has intensified. This research focuses on identifying effective compensation strategies to determine the appropriate advertising investment and trade-in value in a market where two homogeneous retailers compete. Retailers advertise to secure more customers to trade in their used products and to generate more trade-in sales than competitors do. A retailer’s results may vary according to its competitor’s investment strategy, which makes it useful to employ information on past competitor investment patterns to plan future investment strategies. However, as competitors using one another’s information may intensify the competition, better investment results could be obtained by ignoring competitor investment information. Therefore, this study suggests four competition strategies that determine the advertisement costs and trade-in allowance spent by retailers and discusses the difference in the profits obtained by the retailers under each of the four strategies.