Requirement Analysis of an OWL Based Disassembly Planning Information Model

Disassembly, a process of separating the End of Life (EOL) product into discrete components for re-utilizing their associated residual values, is an important part for the sustainable manufacturing. This work focuses on the modeling of the disassembly planning related information, and develops a Disassembly Information Model (DIM) based on an extensive investigation of various informational aspects of the disassembly planning. In this paper, the requirement analysis for the development of the DIM has been carried out and two categories of the requirements relating to the disassembly domain aspect and the information model aspect are thoroughly discussed. Citation: Zhu B, Roy U (2020) Requirement Analysis of an OWL Based Disassembly Planning Information Model. J Robotics Autom 4(1):131142 Zhu and Roy. J Robotics Autom 2020, 4(1):131-142 Open Access | Page 132 | They can be considered as an abstraction of the reality. Graph theory has been used as a powerful tool to solve the problems of disassembly planning, and representation models like connection diagram and AND/OR graph are usually utilized in such methods. The characteristics and functions of a disassembly system are explicitly expressed in the graph, and different searching algorithms are applied to find all the feasible disassembly sequences according to the topological, geometrical and technical constraints. Different strategies are further applied to locate the optimal sequence with consideration of the plan effectiveness and cost-effectiveness. Several outstanding graph-based approaches are briefly discussed below. Penev, et al. [6] used AND/OR graph theory and methods of dynamic programming for the generation and evaluation of the feasible disassembly plans. A new economic model is introduced to determine the optimal disassembly depth. Zhang, et al. [7] developed a graph based heuristic approach for the generation of disassembly sequences from CAD system directly. They proposed a Component-Fastener Graph to analyze the product assembly relationship and a searching for cut-vertex and decomposition of the EOL product into several subassemblies is further applied on the graph to simplify the disassembly analyzing process. Murayma, et al. [8] described the disassembly sequence generation using the idea of information entropy and heuristics to replace components at maintenance stages. The advantage of this method is primarily in the reduction of searching time and searching places for disassembly sequences. The author also developed a software tool integrated with a CAD system and carried out an experiment for an electric drill using the tool. A graph-based information modelling system to represent the process for disassembly and recycle planning of consumer products was proposed by Kanai, et al. [9]. Four kinds of graph have been presented: (1) A configuration graph of sub-assemblies or fragments; (2) A connection graph between parts and materials; (3) A process graph of disassembly, shredding, and sorting activities; (4) A retrieval condition graph. Rules and procedures for transforming the models of these activities are uniformly formulated. A vacuum cleaner is used as an example to demonstrate the proposed graph-based method. Lambert [10] proposed a Linear Programming (LP) model, based again on the AND/OR graph, to the disassembly planning problems. The LP model tries to find the optimal disassembly sequence based on maximizing the total value of the retrieved parts/ subassembly and minimizing the total disassembly operation cost associated with them. Petri net-based approach: Besides the traditional graphbased disassembly analysis approach, Petri-Net (PN), as a graphical and mathematical tool, provides a uniform environment for modelling and analyzing both static and dynamic discrete events. They provide a very promising method for disassembly sequence generation. Zussman, et al. [11] proposed a complete and mathematically sound Disassembly Petri Net (DPN) approach to model the disassembly processes. In their work, the detailed construction and advantages of the proposed DPN have been discussed, and a DPN based searching algorithm has been Things (IoT) and Life Cycle Units (LCU), have already been discussed in the disassembly research community for ideas like future cloud-based remanufacturing [4] and semantic recovery information service [5]. Briefly, IoT provides a network to connect different physical objects, which allows them to be sensed and controlled remotely across existing network infrastructure, creating opportunities for more direct integrations of the physical world into computer-based systems, and resulting in improved efficiency, accuracy and economic benefit. LCU, on the other hand, is developed specifically for the product disassembly process. As mentioned before, in a disassembly factory, different products arrive continuously for disassembly, and individual decisions regarding optimal disassembly sequences have to be made for every product. It is difficult to predict any pre-defined disassembly process sequences a priori, so the detailed information on how to disassemble each arriving product is needed. LCU is proposed for decentralizing that information by integrating a physical device named Life Cycle Units (LCU) into every product. The LCU stores information needed for disassembly. Once enough disassembly information about a product is present, the optimal disassembly sequence can be generated based on the actual physical status of the EOL product. Combining the LCU and IoT technologies together, individualized EOL product information could be sensed and collected by LCU and transferred to the central Product Lifecycle Management (PLM) system through the IoT network. This could be used to tackle the problem of disassembly information bottleneck. In this reported work, we develop a Disassembly Information Model (DIM) that can be integrated into the future sustainable and smart manufacturing environment, for efficient disassembly planning activities. As the first part of this work, detailed requirements regarding the DIM are identified and analyzed in this paper, which looks into both of the disassembly domain aspect and information modelling aspect. An overview of the developed DIM is also briefly presented. A layered Information Model (IM) development methodology is proposed to address the reusability-usability trade-off problem. The developed DIM is further implemented into the Web Ontology Language (OWL), through which relevant information can be computationally analyzed and utilized.