Product Disassembly Research Articles

Approaches and Challenges in Product Disassembly Planning for Sustainability

Due to the vast variety of products and end-of-life uncertainties of used products, product disassembly remains as a challenging research area. This paper aims to address the gap between sustainable product development and product life cycle through optimizing disassembly in each stage of the product life cycle. Firstly, a comprehensive review on design concepts for product development and relevant disassembly planning methodologies at the different phases of a product life cycle, such as Design for Disassembly (DfD), product service system (PSS), disassembly sequence generation (DSG), and reconfigurable disassembly systems (RDS) is presented. Next, a conceptual framework that leverages on emerging technology driven by Industry 4.0 and product family approach to facilitate product disassembly planning for sustainability is proposed. Lastly, a short summary on different challenges presented as well as the respective future work are elaborated.

An approach for agile planning of disassembly and recycling of complex products

Manufacturing companies nowadays are more than ever compelled to adapt to the challenges of constantly changing conditions in the product creation process. The exchange of digital data and data processing are pre-requisites for improvements of agility from initial idea to disassembly and recycling. The 3D PDF format offers not only the ability to visualise 3D data without installing or licensing a CAD system, but also allows the data to be dynamically adjusted, commented and animated in a template container. In this paper, a concept for the use of 3D PDF is presented regarding a defined workflow for disassembly and recycling within the product creation process. After having identified a distinctive field of studies with the help of the model, it is to work out a new use case. Later in the paper, a workflow is developed and finally a prototypical example of the 3D PDF document is implemented.

A Co-evolutionary Algorithm for Open-shop Scheduling with Disassembly Operations

In recent years, many used products are returned from customers through reverse supply chains in order to be reused and recycled. Therefore, it is necessary to provide suitable disassembly procedures from the view point of economic efficiency. This research proposes a scheduling method for open-shop scheduling problems containing both disassembly operations and post-processing operations. A co-evolutionary algorithm is proposed to modify not only the sequences of disassembly and post-processing operations of products but also the sequences of products loaded on disassembly and post-processing machines. Two different kinds of individuals are modeled for both the sequences of operations and the sequences of products in the co-evolutionary algorithm. These individuals alternately repeat evolution at short time intervals, and affect their fitness values each other. We developed a prototype of scheduling system and applied it to some computational experiments for open-shop type scheduling problems including disassembly and post-processing operations. The experimental results of the proposed method were compared with the one of another scheduling method with various heuristic rules in order to evaluate the effectiveness of the proposed method.

Competitive-Cost Analysis: Cost-Modeling Techniques

The second in a series on competitive-cost analysis, this note provides a general discussion of four specific tools that will further assist in analyzing cost drivers for competitive analysis. These techniques include teardown analysis, public data sources, scale curves, and utilization curves. Excerpt UVA-OM-1255 Rev. Aug. 9, 2018 Competitive-Cost Analysis: Cost-Modeling Techniques Competitive-cost analysis, a method for analyzing the cost structures of two competing companies, represents a strategic application of cost modeling. The first note in this three-part series on competitive-cost analysis (see also UVA-OM-1254 and UVA-OM-1256) identified the basic conceptual framework and principles for developing accurate and comprehensive cost models with four categories of cost drivers: design, facility, geography, and execution. This framework, coupled with cost-modeling techniques, can help the operations analyst or consultant achieve the quantitative rigor needed to ensure solid operations decisions at the strategic and tactical levels. This note discusses four tools that can be used to analyze cost drivers: teardown analysis, public data sources, scale curves, and utilization curves. The final note provides step-by-step guidance on estimating scale curves and calculating utilization impact. Teardown Analysis Teardown analysis consists of the physical disassembly and piecemeal analysis of a complete product. Common among engineering organizations, the typical teardown analysis looks at competitors' products to track new features or design choices that could be applied to the company's own products. For example, for many years General Motors (GM) maintained a facility in Detroit that dedicated more than 50,000 square feet to the display of disassembled vehicles from competitors. Engineers from across the company visited the facility (known internally as the “Mona Lisa Center”) to examine specific parts such as the brake system or seat assembly. Such information can prove particularly useful in quantifying the design-driven costs in a competitive-cost analysis. . . .

An approach for agile planning of disassembly and recycling of complex products

An approach for agile planning of disassembly and recycling of complex products

A Process Demonstration Platform for Product Disassembly Skills Transfer

Automated disassembly is challenging due to uncertainties and variations in the process with respect to the returned products. While cognitive robotic disassembly system can dismantle products in most cases, human assistances are required for resolving some physical uncertainties. This article presents a platform that the disassembly process can be demonstrated by skillful human operators. The process is represented with the sequence, position, and orientation of the tools, which are extracted by using vision system and tools’ markers. The knowledge at planning and operational levels will be transferred to the robot to achieve automated disassembly. An operation for removing a back cover of an LCD screen with three disassembly tools is a case study.

A Method for Improving the Process and Cost of Nondestructive Disassembly

The ever-increasing global environmental concerns demand that strong emphasis be given to the decision-making process pertaining to the strategy of design for nondestructive disassembly during the product evaluation stage. The ultimate objective is to considerably increase the percentage of product components and materials suitable for recycling, recovery, and/or reuse. In this context, this paper proposes a method for improving the nondestructive disassembly of a final product. This method analyzes the nondestructive disassembly by determining a disassembly interference matrix, feasible disassembly sequences, and improved nondestructive disassembly sequences. The innovative element of the nondestructive disassembly method proposed in this paper is integrating the generated conceptual design solutions for a given technical device with a software package developed for determining its improved disassembly sequence embedded within a 3D CAD platform. The developed procedure is based on information obtained from a 3D CAD model of a product, such as geometric constraints, automatic identification of fasteners and components, determination of component-to-component and component-to-fastener connection graphs, and AND/OR logic operations. The goal is for product designers to predict, evaluate, and define improved disassembly sequences while minimizing the cost of disassembly operations as early in the design stage as possible after a CAD model of the product becomes available. The applicability of the integrated method for determining the improved disassembly sequence is presented through an illustrative example.

Ontology and CBR based automated decision-making method for the disassembly of mechanical products

This paper proposes an ontology and CBR (case-based reasoning) based method which overcomes the difficulty for computers to understand complex structures of various mechanical products and makes the disassembly decision-making process of the products fully automated and cost-saving. In this method, (1) ontology concept is applied to the disassembly decision-making. This enables computers to understand and self-reason the CBR/RBR (rule-based reasoning) based disassembly decision-making process. Since ontology uniforms different kinds of disassembly-related knowledge from different sources, the integration and sharing of the knowledge could be achieved; (2) high flexible decision-making to various conditions with high quality is achieved by the combination of ontology and CBR; (3) to achieve the decision-making when CBR fails, an ontology based RBR method is designed to complement the shortage of CBR in the disassembly decision-making field. The paper also presents an application program to realise the proposed method. In addition, a case study is analysed to verify the validity and automation of the program.

A new model for estimating End-of-Life disassembly effort during early stages of product design

In this paper, a new model for estimating disassembly effort during early stages of product design is proposed. The model has been developed by integrating two well-known models in the field of product disassembly: Das et al. Disassembly Effort Index (DEI) model and Kroll and Hanft Disassembly Evaluation model. The first one is a multi-factor cost and effort model, which is widely used for determining disassembly effort in terms of a DEI score. This score is a representative of the total operating cost incurred in disassembling a product. The second model is commonly used for evaluating ease of disassembly, by assigning task difficulty scores to disassembly tasks. Data necessary for determining these scores are obtained from work-measurement analyses of standard disassembly tasks. The proposed model has been demonstrated by an estimation of disassembly effort for a CRT monitor disassembly process using the model and validated by benchmarking the results obtained using the proposed model against results from an existing model for a case study conducted on fifteen computer electronic products.

ControlIt! — A Software Framework for Whole-Body Operational Space Control

Whole Body Operational Space Control (WBOSC) enables floating-base highly redundant robots to achieve unified motion/force control of one or more operational space objectives while adhering to physical constraints. It is a pioneering algorithm in the field of human-centered Whole-Body Control (WBC). Although there are extensive studies on the algorithms and theory behind WBOSC, limited studies exist on the software architecture and APIs that enable WBOSC to perform and be integrated into a larger system. In this paper, we address this by presenting ControlIt!, a new open-source software framework for WBOSC. Unlike previous implementations, ControlIt! is multi-threaded to increase maximum servo frequencies using standard PC hardware. A new parameter binding mechanism enables tight integration between ControlIt! and external processes via an extensible set of transport protocols. To support a new robot, only two plugins and a URDF model is needed — the rest of ControlIt! remains unchanged. New WBC primitives can be added by writing Task or Constraint plugins. ControlIt!’s capabilities are demonstrated on Dreamer, a 16-DOF torque controlled humanoid upper body robot containing both series elastic and co-actuated joints, and using it to perform a product disassembly task. Using this testbed, we show that ControlIt! can achieve average servo latencies of about 0.5[Formula: see text]ms when configured with two Cartesian position tasks, two orientation tasks, and a lower priority posture task. This is 10 times faster than the 5[Formula: see text]ms that was achieved using UTA-WBC, the prototype implementation of WBOSC that is both application and platform-specific. Variations in the product’s position is handled by updating the goal of the Cartesian position task. ControlIt!’s source code is released under LGPL and we hope it will be adopted and maintained by the WBC community for the long term as a platform for WBC development and integration.

A New Model to Select Fasteners in Design for Disassembly

Product disassembly will only take place if there is enough generated profit. But as the end-of-life is often overlooked during the design process it makes the disassembly hard to perform and therefore the profitability is especially reduced. Design for disassembly is one of proposed solutions and fasteners are one of the points that have most impact on the disassembly of products. The aim of the proposed model is to determine among several alternatives which one allows to meet the requirements in assembly, in-use, services and disassembly. The model takes into account the semi-destructive disassembly (deteriorate a part of a sub-assembly to recover valuable components or materials and while reducing the disassembly time without important value loss). The model developed in this paper is mainly based on the Analytic Network Process (ANP) to define the best alternative and make the fastener selection during the design process easily. An example is presented for a better comprehension.

GEN-PRODIS Approach for Determining Total Cost in Disassembly Sequencing Problem<sup></sup>

Disassembly sequence planning not only reduces product life cycle cost, but also greatly influences environmental impact. Industrial recycling and remanufacturing involves product disassembly to retrieve the desired parts and/or subassemblies by separating a product into its constituents. Disassembly has recently gained a great deal of attention in the literature due to its role in product recovery. Disassembly sequencing and planning is more challenging than assembly because its terminal goal is not necessarily fixed, but may depend on product usage and market demands for used parts and recycled materials. Moreover, disassembly is accompanied by more uncertainty in system structures and component conditions than is assembly. This paper presents recent methods for sequencing and process planning in disassembly and the applications to industrial products. This research is aimed at determining the optimal disassembly sequence as well as the helps to find the sequence dependent cost.

Disassembly Sequence Optimization for Large-Scale Products With Multiresource Constraints Using Scatter Search and Petri Nets.

Disassembly modeling and planning are meaningful and important to the reuse, recovery, and recycling of obsolete and discarded products. However, the existing methods pay little or no attention to resources constraints, e.g., disassembly operators and tools. Thus a resulting plan when being executed may be ineffective in actual product disassembly. This paper proposes to model and optimize selective disassembly sequences subject to multiresource constraints to maximize disassembly profit. Moreover, two scatter search algorithms with different combination operators, namely one with precedence preserved crossover combination operator and another with path-relink combination operator, are designed to solve the proposed model. Their validity is shown by comparing them with the optimization results from well-known optimization software CPLEX for different cases. The experimental results illustrate the effectiveness of the proposed method.

Probability Evaluation Modeling and Planning of Product Disassembly Profit

Disassembly modeling and planning is meaningful and instructive for remanufacturing and recycling of disused products. However, an actual disassembly process of products has uncertainties since a variety of unpredictable factors. To handle such uncertainty, this work presents a novel disassembly modeling and planning approach using an extended stochastic Petri nets. An extended stochastic disassembly Petri nets (ESDPN) model is defined to provide basis for disassembly planning. Moreover, based on it, some typical probability evaluation models is built accordion to different disassembly criterion. In addition, a hybrid intelligent integrating stochastic simulation and neural network (NN) is proposed to solve the proposed models, respectively. Some numerical examples are given to illustrate the proposed models and the effectiveness of proposed algorithms.

Disassembly line balancing under high variety of end of life states using a joint precedence graph approach

Disassembly is an important aspect of end of life product treatment, as well as having products disassembled in an efficient and responsible manner. Disassembly line balancing is a technique that enables a product to be disassembled as efficiently and economically viable as possible; however, considering all possible end of life (EOL) states of a product makes disassembly line balancing very difficult. The EOL state and the possibility of multiple recovery options of a product can alter both disassembly tasks and task times for the disassembly of the EOL product. This paper shows how generating a joint precedence graph based on the different EOL states of a product is beneficial to achieving an optimal line balance where traditional line balancing approaches are used. We use a simple example of a pen from the literature to show how a joint disassembly precedence graph is created and a laptop example for joint precedence graph generation and balancing. We run multiple scenarios where the EOL conditions have different probabilities and compare results for the case of deterministic task times. We also consider the possibility where some disassembly task times are normally distributed and show how a stochastic joint precedence graph can be created and used in a stochastic line balancing formulation.

Assembly oriented control algorithm of collaborative disassembly and assembly operation in collaborative virtual maintenance process

Maintenance data and information processing is an essential and important problem in collaborative virtual maintenance of complex equipments. Significant research has been done in this paper to provide an efficient approach to performing the data and information processing of collaborative virtual disassembly and assembly operations. Assembly oriented mathematical model of collaborative virtual maintenance operation process is presented with the behavior representation and information description of each component in an assembly based on single object oriented modeling of collaborative maintenance operation as well as assembly oriented modeling of disassembly and assembly operations. Assembly oriented control algorithms of disassembly and assembly operations in collaborative virtual maintenance process are also designed to perform the required data and information processing. With the object information template based on Extensible Markup Language, proposed mathematical models and control algorithms are utilized in a technical experiment system with high reliability and efficiency. Experimental implementation has been done to find appropriate and efficient mathematical models and control algorithms can support effectively the data and information processing of collaborative virtual disassembly and assembly operations of complex products. Methodologies developed in this paper extend the previous work on mathematical modeling and information processing complexity, and improve the reliability and efficiency of required data and information processing in collaborative virtual maintenance process.

Developing a bi-objective model of the closed-loop supply chain network with green supplier selection and disassembly of products: The impact of parts reliability and product greenness on the recovery network

Closed-loop supply chain network (CLSCN) design aims to incorporate environmental considerations into the traditional supply chain design by including recycling, disassembly and reuse activities. A CLSCN incorporates the use and reuse of environmentally friendly products and materials supported by the design of an appropriate recovery, disassembly, and refurbishing network. In the design process, a trade-off must often be made between the need to maximize profit and maximize greenness. The latter is considered for several reasons including regulatory requirements, corporate responsibility and corporate image. In this paper, a bi-objective mixed integer programming model is developed and solved for a forward/reverse logistic network including three echelons in the forward direction (suppliers, assembly centers and customer zones) and two echelons in the reverse direction (disassembly and recycling center). A set of Pareto optimal solutions is obtained to show the trade-off between the profit and the greenness objectives. Some useful managerial insights are developed through various computational experiments.

Selective disassembly sequence generation based on lowest level disassembly graph method

Integration of disassembly operations during product design is an important issue today. As known, the number of possible disassembly sequences increases significantly with the number of parts in a product. Thus, generating proper disassembly sequences is critical. Most existing methods often require tremendous computational resources, while, at the same time, they often fail to find realistic and optimal solutions for complex product disassembly. For selective disassembly, for instance, it is important to eliminate the components which are unrelated with the target prior to sequence generation. In order to address this configuration, this paper deals with a method for generating the feasible disassembly sequences for selective disassembly. It is based on the lowest levels of a disassembly product graph. Instead of considering the geometric constraints for each pair of components, the proposed method considers the geometric contact and collision relationships among the components in order to generate the proposed disassembly geometry contacting graph (DGCG). The generation of the disassembly sequences is based on the investigated three cases called micro-units, which consider all the possible situations of relationships among the components in the DGCG. The latter is then used for disassembly sequence generation, thus allowing decreasing the number of possible disassembly sequences. For this purpose, a mixed Virtual Reality Disassembly Environment (VRDE) is developed based on Python programming language using mixed Visualization Toolkit (VTK) and Open Dynamics Engine (ODE) libraries. It is applied for automatic generation of the selective disassembly sequences and is illustrated within two examples.

Two-stage Sequence Generation for Partial Disassembly of Products with Sequence Dependent Task Times

For disassembly sequence generation, partial disassembly and sequence dependent task times are typically not considered together in the same model. We developed a two-stage optimization program that first determines the optimal partial disassembly sequence according to reuse value only, followed by the second stage that finds the optimal partial disassembly sequence that also includes sequence dependence task times. We prove the optimality of the two-stage approach under the condition that all components with any positive reuse value must be included in the final sequence. If this condition does not need to be met, a task hedging policy is shown to be effective.

Solution space reduction of disassembly sequences generated automatically via computer aids

To develop a simulation tool for automatic disassembly in computer aid design (CAD) environment two difficulties are found: the huge space of generated sequences and their feasibility especially in combinatory generation. This article deals with automatic sequence generation for selective disassembly of mechanical product. Starting from a CAD model a new appropriate connection tree of a target component is constructed. This tree aims at reducing space solution by eliminatory rules. The generation of sequence is based on reading of connection tree branches and eliminatory tests of feasibility. The feasibility is checked by updating the disassembly mobility of each sequence’s element. A case study is presented to prove the effectiveness of the proposed approach.