Simulation of service-oriented and distributed manufacturing systems

In this paper modeling and simulation is discussed in the context of distributed manufacturing systems (DiMS). The DiMS concept aims towards efficient and innovative collaboration that integrates design and development activities of manufacturing systems. A DiMS, described formally as a digital manufacturing system, is a competent basis for the modeling and simulation of manufacturing systems. The activities of the simulation model are described on the basis of a service-oriented approach in which content of the services is completely known. Micro, meso, and macro manufacturing levels are applied to the modeling and simulation. By means of these levels the hierarchy of the communication of the services is illustrated. An example is described in which modeling and simulation is used to proceed from ideas to efficiently operated manufacturing systems.     

Work design and analysis for space-based manufacturing: a case analysis of initial design issues

The purpose of the present research was to investigate the nature of potential manufacturing tasks humans may execute in a space environment. The success of space-based manufacturing (SBM) is suggested to be a precursor to permanent human presence in space. A working hypothesis for this study was that human work in the SBM environment would be substantially different from terrestrial manufacturing work. To investigate this hypothesis, a case analysis approach was developed that employed a function allocation and task analysis of a representative SBM process: the production of tailored industrial crystals. This research approach was chosen as the current state of engineering design for SBM is in the conceptual and early flow sheeting phases of a system life cycle. Results of the task analysis and function allocation process suggest response to corrective maintenance functions and to abnormal system conditions should be allocated to humans as opposed to automation. These results are discussed in relation to human factors engineering challenges associated with long-duration human presence in an SBM environment.     

Key factors for operational performance in manufacturing systems: Conceptual model,systematic literature review and implications

PurposeThe performance of discrete items manufacturing systems (MS) is a primary concern of industrial firms. However, the understanding of the interrelations between performance and its key factors requires further advancements. Thus, several questions remain unanswered in the Operations and Production Management (OPM) field to understand and manage the relationship between these key factors. To address these challenges, this paper conceptualizes and examines the relevant antecedents and essential elements for the design and optimization of competitive MS.Design/methodology/approachFirst, drawing on the consolidated OPM literature, a novel conceptual model was developed incorporating the conceptual relationships essential to MS performance. Second, we conducted a systematic literature review based on the PRISMA protocol to analyze and validate the proposed conceptual model and to indicate the field’s current knowledge gaps and future research directions.FindingsFindings validated the proposed conceptual model by establishing the complex causal interrelations among key factors that influence discrete MS performance. Moreover, we found that the operational performance of discrete MS is multidimensional and directly dependent on the variables and mechanisms associated with the production flow. Findings also demonstrated that the degree of importance of the antecedents of MS performance vary and are temporally interrelated. Lastly, the paper advances the understanding of MS by revealing the predominance of quantitative approaches (e.g., discrete events simulation and closed mathematical models) in the literature as well as an emphasis on describing these approaches rather than characterizing MS appropriately.Research and Practical implicationsThis paper extends our knowledge on the operational performance challenges in discrete MS by proposing a visual, direct, and intuitive conceptual model that enables firms to better comprehend these complex challenges. This research also answers ongoing calls for investigations of the antecedents and elements of competitive MS design and optimization. Our findings show that decision-making in discrete MS is established temporally based on strategic, operational, and control definitions, influencing firms’ operational performance. Finally, since it draws on seminal OPM literature specializing in MS, this study informs scholars, industrial managers, and aid decision-making about discrete MS.Originality/valueThe first original aspect of this study lies in bridging the gaps identified in the OPM literature by providing a robust conceptual framework that highlights the key factors of operational performance in discrete MS. Its second original aspect is that it adopts different information sources in an independent and complementary way to achieve greater generalizability and robustness of the contributions.     

Graphical and text-based design interfaces for parameter design of an I-beam,desk lamp,aircraft wing,and job shop manufacturing system

In this paper we describe four design optimization problems and corresponding design interfaces that have been developed to help assess the impact of fast, graphical interfaces for design space visualization and optimization. The design problems involve the design of an I-beam, desk lamp, aircraft wing, and job shop manufacturing system. The problems vary in size from 2 to 6 inputs and 2 to 7 outputs, where the outputs are formulated as either a multiobjective optimization problem or a constrained, single objective optimization problem. Graphical and text-based design interfaces have been developed for the I-beam and desk lamp problems, and two sets of graphical design interfaces have been developed for the aircraft wing and job shop design problems that vary in the number of input variables and analytical complexity, respectively. Response delays ranging from 0.0 to 1.5 s have been imposed in the interfaces to mimic computationally expensive analyses typical of complex engineering design problems, allowing us to study the impact of delay on user performance. In addition to describing each problem, we discuss the experimental methods that we use, including the experimental factors, performance measures, and protocol. The focus in this paper is to publicize and share our design interfaces as well as our insights with other researchers who are developing tools to support design space visualization and exploration.     

A toolbox for the design,planning and operation of manufacturing networks in a mass customisation environment

The task of design, planning and operation of manufacturing networks is becoming more and more challenging for companies, as globalisation, mass customisation and the turbulent economic landscape create demand volatility, uncertainties and high complexity. In this context, this paper investigates the performance of decentralised manufacturing networks through a set of methods developed into a software framework in a toolbox approach. The Tabu Search and Simulated Annealing metaheuristic methods are used together with an Artificial Intelligence method, called Intelligent Search Algorithm. A multi-criteria decision making procedure is carried out for the evaluation of the quality of alternative manufacturing network configurations using multiple conflicting criteria including dynamic complexity, reliability, cost, time, quality and environmental footprint. A comparison of the performance of each method based on the quality of the solutions that it provided is carried out. The statistical design of experiments robust engineering technique is used for the calibration of the adjustable parameters of the methods. Moreover, the impact of demand fluctuation to the operational performance of the alternative networks, expressed thorough a dynamic complexity indicator, is investigated through simulation. The developed framework is validated through a real life case, with data coming from the CNC machine building industry.     

Simulation and graphical animation of advanced manufacturing systems

Automated production systems, known as Flexible Manufacturing Systems (FMS), offer a promising solution for the low productivity of mid-volume, mid-variety batch production. These systems consist of integrated machine modules and material handling equipment under computer control.This paper describes a general purpose discrete-event Flexible Manufacturing Systems Simulator (FMSSIM). The package is programmed in FORTRAN and is capable of simulating different configurations, material handling systems, and topologies including bidirectional tracks. The simulator checks blockage of routes due to interference of carts and simulates random failures and repairs of the various components in the system. The simulator provides the user with a wide range of priority rules to select from, and enables the user to define his own rules if required. The simulator produces reports on various vital system performance statistics and also displays the movement of parts through the system on a refreshed CRT. This simulator is a modular, user-oriented package which allows the designer to evaluate a wide range of systems with varied design parameters and select an efficient flexible manufacturing system. Some general trends in the behaviour of the flexible manufacturing systems are identified and guidelines for their design and operation are suggested.     

Digital twins-based smart manufacturing system design in Industry 4.0: A review

A smart manufacturing system (SMS) is a multi-field physical system with complex couplings among various components. Usually, designers in various fields can only design subsystems of an SMS based on the limited cognition of dynamics. Conducting SMS designs concurrently and developing a unified model to effectively imitate every interaction and behavior of manufacturing processes are challenging. As an emerging technology, digital twins can achieve semi-physical simulations to reduce the vast time and cost of physical commissioning/reconfiguration by the early detection of design errors/flaws of the SMS. However, the development of the digital twins concept in the SMS design remains vague. An innovative Function-Structure-Behavior-Control-Intelligence-Performance (FSBCIP) framework is proposed to review how digital twins technologies are integrated into and promote the SMS design based on a literature search in the Web of Science database. The definitions, frameworks, major design steps, new blueprint models, key enabling technologies, design cases, and research directions of digital twins-based SMS design are presented in this survey. It is expected that this survey will shed new light on urgent industrial concerns in developing new SMSs in the Industry 4.0 era.     

基于多Agent的可重构制造系统集成模型

应用控制、管理和维护一体化的自动化技术,建立了基于多Agent的可重构制造系统RMS（Reconfigurable Manufacturing System）集成模型。该模型集成了基于多Agent 的RMS重构模型、控制模型和故障诊断模型,将RMS的控制、管理和维护联系起来,并给出了该模型的UML（Unified Modeling Langurage）活动图,最后举例验证了模型的可行性。     

Interoperability of manufacturing applications using the Core Manufacturing Simulation Data (CMSD) standard information model

The goal of this paper is to propose an approach to enhance interoperability between manufacturing applications using the Core Manufacturing Simulation Data Information Model (CMSDIM) in order to streamline design and manufacturing activities throughout the product life cycle. To this end, a system framework required to facilitate such interoperability is first presented. The proposed approach, architecture, and developed translators are then illustrated and demonstrated using two separate case studies. The first case study facilitates design for manufacturing and assembly improvements for the development of new products, allowing for part of a discrete event simulation model of a downstream manufacturing and assembly process to be automatically generated from corresponding product assembly information contained in the lean design engineering software. Conceptual design and development of this case study, which extracts outputs from Design Profit™ lean design software and generates a corresponding discrete event simulation model in ProModel™ for a Nikon® L-100 Camera, is then discussed. The second case study demonstrates interoperability of three applications (order and inventory system, Gantt chart scheduler, and discrete event simulation) for a generic job shop operation. Using the considered case studies, this paper also details and demonstrates the benefits of interoperability enhancement using the CMSDIM, which is an important consideration in any product life cycle. Finally, we discuss how future research opportunities integrating additional manufacturing applications can be used to address intellectual challenges present in our current approach.     

Supporting management and maintenance of manufacturing knowledge in design automation systems

Many companies base their business strategy on customized products. To enable a high level of product adaptation in an engineer-to-order approach companies invest time and resources to develop design automation systems. Initially, when implementing a design automation system, the focus is on successfully developing a system that generates design variants based on different customer specifications (i.e. the execution of system embedded knowledge and system output). However, in the long run, two important aspects are the management and maintenance of the knowledge that governs the designs. Further, the increasing emphasis on deploying a holistic view of a product’s properties and functions implies an increasing number of life-cycle requirements. The knowledge to adapt the product to fulfil these requirements should also be used and consequently incorporated into the knowledge-base, allowing for correct decisions to be made. In a system for automated variant design, the implications on the product of these life-cycle requirements have to be expressed as algorithms, production rules and/or computational statements to be intertwined with the design calculations. The number of requirements can be significantly large, and the knowledge scattered over different application systems used for the realisation of the design automation system. This makes it difficult to manage and maintain the system as the product life-cycle environment changes and evolves.In this article, the focus is on the requirements related to manufacturing. For that, an approach for the modelling of manufacturing requirements, supporting both knowledge execution and information management, in systems for automated variant design is introduced. The approach has been applied and refined when developing a design automation system in cooperation with a company to demonstrate and verify the approach’s usability.     

Perturbation analysis for production control and optimization of manufacturing systems

We use stochastic fluid models (SFM) to capture the operation of threshold-based production control policies in manufacturing systems without resorting to detailed discrete event models. By applying infinitesimal perturbation analysis (IPA) to a SFM of a workcenter, we derive gradient estimators of throughput and buffer overflow metrics with respect to production control parameters. It is shown that these gradient estimators are unbiased and independent of distributional information of supply and service processes involved. In addition, based on the fact that they can be evaluated using data from the observed actual (discrete event) system, we use them as approximate gradient estimators in simple iterative schemes for adjusting thresholds (hedging points) on line seeking to optimize an objective function that trades off throughput and buffer overflow costs.     

一种仿真系统的HLA兼容性改造方法

HLA是建模和仿真领域的通用技术框架,旨在实现仿真重用和仿真互操作。建立HLA仿真系统的方法既可以按照HLA规范重新进行开发,也可以对通过现有的仿真系统进行兼容性改造。其中后一种方法可以节省投资,减少开发工作量,提高开发效率。由于现有的各种仿真系统的结构和设计方法的不同,实现HLA兼容性改造的方法也不尽相同。该文从现有仿真系统(基于组件的建模仿真环境,CBMSE)的特点出发,提出了一种HLA兼容性改造的方法。     

Production decision support system for computerized manufacturing systems

The introduction of Computerized Manufacturing Systems (CMS) into the mid-volume manufacturing industry has been an important new step in the development of automated manufacturing. CMS's are computer-integrated systems which incorporate Direct Numerical Control (DNC) capabilities with automatic material handling to manufacture parts. Due to its complex nature, the task of production control in an CMS cannot rely on human effort alone. It is essential to develop a software package in the form of a Production Decision Support System (PDSS) to assist the production decision maker in operating this complex manufacturing facility.     

A decision support system for cellular manufacturing system design

With the growth of competitive pressure in the global markets, there has been an increase in demand in industry for cellular manufacturing systems (CMSs) in order to improve productivity and process flexibility. The design of CMSs for industrial applications is a complex and knowledge intensive process as it involves the consideration of many factors including production data and process characteristics. This paper describes the development and implementation of a decision support system for the feasibility and conceptual design of CMSs. The system is based on the knowledge-based system approach, and is able to make recommendations of system feasibility, cell formation techniques and cell types. A case study is also presented to demonstrate the capability of the decision support system.     

The application of manufacturing culture to the design of Asian region oriented machine tools

During the last years the demand for regionally and culturally harmonised machine design is increasingly on the agenda. The problem of localising products like machine tools instantly poses the question for new procedures that allow including the regional and cultural adaptations into the design processes of machine tool companies. How to transform the general insight into the necessity of culture- and region-adapted technologies and how to embed it into a design procedure comprising applicable design attributes is the crucial problem addressed. The paper shows in an exemplary way how ambiguous design attributes can eventually be embodied in a prototype design.     

Automated manufacturing system discovery and digital twin generation

The latest developments in industry involved the deployment of digital twins for both long and short term decision making, such as supply chain management, production planning and control. Modern production environments are frequently subject to disruptions and consequent modifications. As a result, the development of digital twins of manufacturing systems cannot rely solely on manual operations. Recent contributions proposed approaches to exploit data for the automated generation of the models. However, the resulting representations can be excessively accurate and may also describe activities that are not significant for estimating the system performance. Generating models with an appropriate level of detail can avoid useless efforts and long computation times, while allowing for easier understanding and re-usability. This paper proposes a method to automatically discover manufacturing systems and generate adequate digital twins. The relevant characteristics of a production system are automatically retrieved from data logs. The proposed method has been applied on two test cases and a real manufacturing line. The experimental results prove its effectiveness in generating digital models that can correctly estimate the system performance.     

浅析沙角A电厂5号机组FGD装置烟气系统的设计和运行

概述了广东省第一台300MW燃煤机组-沙角A电厂5号机组采用湿法脱硫投产后取得的成效,介绍了石灰石-石膏湿法脱硫装置烟气系统的设计情况,重点介绍烟气系统的运行情况,对存在的问题提出建议。     

Towards a generic design method for reconfigurable manufacturing systems: Analysis and synthesis of current design methods and evaluation of supportive tools

In today’s global manufacturing environment, changes are inevitable and something that every manufacturer must respond to and take advantage of, whether it is in regards to technology changes, product changes, or changes in the manufacturing processes. The reconfigurable manufacturing system (RMS) meets this challenge through the ability to rapidly and efficiently change capacity and functionality, which is the reason why it has been widely labelled the manufacturing paradigm of the future. However, design of the RMS represents a significant challenge compared to the design of traditional manufacturing systems, as it should be designed for efficient production of multiple variants, as well as multiple product generations over its lifetime. Thus, critical decisions regarding the degree of scalability and convertibility of the system must be considered in the design phase, which affects the abilities to reconfigure the system in accordance with changes during its operating lifetime. However, in current research it is indicated that conventional manufacturing system design methods do not support the design of an RMS and that a systematic RMS design method is lacking, despite the fact that numerous contributions exist. Moreover, there is currently only limited evidence for the breakthrough of reconfigurability in industry. Therefore, the research presented in this paper aims at synthesizing current contributions into a generic method for RMS design. Initially, currently available design methods for RMS are reviewed, in terms of classifying and comparing their content, structure, and scope, which leads to a synthesis of the reviewed methods into a generic design method. In continuation of this, the paper includes a discussion of practical implications related to carrying out the design, including an identification of potential challenges and an assessment of which tools that can be applied to support the design. Conclusively, further areas for research are indicated, which provides valuable knowledge of how to develop and realize the benefits of reconfigurability in industry.     

A design of a controller as a component of a robotic manufacturing system

This paper specifies the functional design of a robot or machine tool controller suitable for inclusion in robotic manufacturing systems. The principle interest is the unmanned manufacturing cells which are being developed as major components of new manufacturing facilities. The functional specifications are motivated by recent experiences with the creation of a prototype cell for an open die forging process. There are two key technical design requirements. The first relates to the robot or machine tool being controlled. The controller must direct the machine actions, and, for unmanned operation, the controller must receive and process sensor information for process modification and for fault tolerance. The second relates to communication with the central cell computer (the host). The operation of an unmanned system requires a robot communication channel between the host and the controller; the controller must also respond to a variety of instructions transmitted from the host. Additional controller design requirements are imposed by economics. The proposed controller can be used today, and can develop in an evolutionary manner to meet the needs of future manufacturing systems. The evolutionary development is made possible by modular design, organized in a hierarchical manner.     

An integrated form-feature-based design system for manufacturing

Much of the knowledge that is applied in or communicated between design and manufacturing activities is primarily shape based or shape indexed. Previous attempts to acquire and organize shape knowledge have been mostly concentrated on feature recognition from solid models, group technology (GT) coding schemes, and feature-based modeling. This paper presents the development of an efficient form-feature-based modeling system, and addresses the important issue of utilizing feature information for manufacturing, which has not been extensively discussed by previous work. In this paper we first present a Euler operator-based approach for efficient and effective form-feature encoding and manipulation in a feature-based design environment. Subsequently, a hybrid representation scheme called enhanced CSG tree of feature (ECTOF), which integrates feature model with solid model in a tree structure, is discussed. A feature interference resolution methodology to maintain the correct and consistent feature information in an ECTOF is also deliberated. Finally, we present a machinability-checking module, which employs global accessibility criteria to analyze a feature's machinability on a three-axis machining center. By developing feature interference resolving and machinability testing techniques and integrating with an efficient feature-based design system, this research makes the development of an integrated feature-based design and manufacturing system possible.