Simulation in manufacturing and business: A review

Copyright @ 2009 Elsevier B.V.This paper reports the results of a review of simulation applications published within peer-reviewed literature between 1997 and 2006 to provide an up-to-date picture of the role of simulation techniques within manufacturing and business. The review is characterised by three factors: wide coverage, broad scope of the simulation techniques, and a focus on real-world applications. A structured methodology was followed to narrow down the search from around 20,000 papers to 281. Results include interesting trends and patterns. For instance, although discrete event simulation is the most popular technique, it has lower stakeholder engagement than other techniques, such as system dynamics or gaming. This is highly correlated with modelling lead time and purpose. Considering application areas, modelling is mostly used in scheduling. Finally, this review shows an increasing interest in hybrid modelling as an approach to cope with complex enterprise-wide systems

Simple network management protocol co- existence with hydrocarbon process automation communication real-time network

Hydrocarbon Process Automation Applications (HPAA) utilizes Real-time network connecting process instrumentations, controllers, and real-time logic control applications. Conventional practice is to dedicate a real-time network for process automation applications and prevent other applications from utilizing the same infrastructure. An important application that can help optimize, improve network performance, and provide rapid response time in network diagnostics and mitigation is Simple Network Management Protocol (SNMP). This paper addresses the co-existence of SNMP traffic with real-time applications. The impacts of activating this protocol with the real-time HPAA utilizing high speed Ethernet network design will be examined. Empirical data for an implemented Hydrocarbon process automation system will be used to illustrate the interdependency of application performance, traffic mix, and potential areas of improvements. The outcomes of this effort demonstrate the co-existence of SNMP with HPPA, given special considerations (i.e., bandwidth, number of applications, etc.)

Towards a semantic Construction Digital Twin: directions for future research

As the Architecture, Engineering and Construction sector is embracing the digital age, the processes involved in the design, construction and operation of built assets are more and more influenced by technologies dealing with value-added monitoring of data from sensor networks, management of this data in secure and resilient storage systems underpinned by semantic models, as well as the simulation and optimisation of engineering systems. Aside from enhancing the efficiency of the value chain, such information-intensive models and associated technologies play a decisive role in minimising the lifecycle impacts of our buildings. While Building Information Modelling provides procedures, technologies and data schemas enabling a standardised semantic representation of building components and systems, the concept of a Digital Twin conveys a more holistic socio-technical and process-oriented characterisation of the complex artefacts involved by leveraging the synchronicity of the cyber-physical bi-directional data flows. Moreover, BIM lacks semantic completeness in areas such as control systems, including sensor networks, social systems, and urban artefacts beyond the scope of buildings, thus requiring a holistic, scalable semantic approach that factors in dynamic data at different levels. The paper reviews the multi-faceted applications of BIM during the construction stage and highlights limits and requirements, paving the way to the concept of a Construction Digital Twin. A definition of such a concept is then given, described in terms of underpinning research themes, while elaborating on areas for future research

Human intervention and interface design in automation systems

Human-Machine-Interfaces are with no doubt one of the constitutive parts of an automation system. However, it is not till recently that they have received appropriate attention. It is because of a major concern about aspects related to maintenance, safety, achieve operator awareness, etc has been gained. Even there are in the market software solutions that allow for the design of efficient and complex interaction systems, it is not widespread the use of a rational design of the overall interface system, especially for large scale systems where the monitoring and supervision systems may include hundreds of interfacing screens. It is on this respect hat this communication provides an example of such development also by showing how to include the automation level operational modes into the interfacing system. Another important aspect is how the human operator can enter the control loop in different ways, and such interaction needs to be considered as an integral part of the automation procedure as well as the communication of the automation device.In this paper the application of design and operational modes guidelines in automation are presented inside an educational flexible manufacturing system case study.Postprint (published version

Axiomatic Design: 30 Years After

In 1977, Nam P Suh proposed a different approach to design research. Suh’s approach was different in that it introduced the notions of domains and layers in a 2-D design thinking and stipulated a set of axioms that describes what is a good design. Following Suh’s 2-D reasoning structure in a zigzagging manner and applying these axioms through the design process should enable the designer to arrive at a good design. In this paper, we present our own experiences in applying Suh’s theories to software design, product design, organizational design, process design, and more in both academic and industrial settings. We also share our experience from teaching the Axiomatic Design theory to students at universities and engineers in industry, and draw conclusions on how best to teach and use this approach, and what results one can expect. The merits of the design axioms are discussed based on the practical experiences that the authors have had in their application. The process developed around the axioms to derive maximum value (solution neutral environment, design domains, what-how relationship, zig-zag process, decomposition, and design matrices) is also discussed and some updates are proposed

Towards Deterministic Communications in 6G Networks: State of the Art, Open Challenges and the Way Forward

Over the last decade, society and industries are undergoing rapid digitization that is expected to lead to the evolution of the cyber-physical continuum. End-to-end deterministic communications infrastructure is the essential glue that will bridge the digital and physical worlds of the continuum. We describe the state of the art and open challenges with respect to contemporary deterministic communications and compute technologies: 3GPP 5G, IEEE Time-Sensitive Networking, IETF DetNet, OPC UA as well as edge computing. While these technologies represent significant technological advancements towards networking Cyber-Physical Systems (CPS), we argue in this paper that they rather represent a first generation of systems which are still limited in different dimensions. In contrast, realizing future deterministic communication systems requires, firstly, seamless convergence between these technologies and, secondly, scalability to support heterogeneous (time-varying requirements) arising from diverse CPS applications. In addition, future deterministic communication networks will have to provide such characteristics end-to-end, which for CPS refers to the entire communication and computation loop, from sensors to actuators. In this paper, we discuss the state of the art regarding the main challenges towards these goals: predictability, end-to-end technology integration, end-to-end security, and scalable vertical application interfacing. We then present our vision regarding viable approaches and technological enablers to overcome these four central challenges. Key approaches to leverage in that regard are 6G system evolutions, wireless friendly integration of 6G into TSN and DetNet, novel end-to-end security approaches, efficient edge-cloud integrations, data-driven approaches for stochastic characterization and prediction, as well as leveraging digital twins towards system awareness.Comment: 22 pages, 8 figure

Monitoring and control of electrothermal swing adsorption based on electrical properties of the adsorbent

Organic vapors and gases (e.g., toluene and isobutane, respectively) are used in industry to produce a variety of products (e.g., coatings and packaging materials). During production and use of these products, these vapors/gases are often emitted in dilute concentrations, causing adverse health effects and photochemical reactions that increase ground-level ozone concentration. Thermal oxidization is often used for vapor/gas disposal (ideal conversion to H2O and CO2). Capturing and recovering vapors/gases can reduce cost by providing feedstock for production and eliminate emissions from thermal oxidation. A bench-scale electrothermal swing adsorption (ESA) system that uses activated carbon fiber cloth (ACFC) to selectively remove vapors/gases from gas streams and electrothermal heating to regenerate the ACFC was previously developed. This system concentrates a vapor/gas to > 50 % by volume allowing for condensation for reuse as a liquid. Typically, the end of an ACFC-ESA adsorption cycle and the heating part of a regeneration cycle are determined based on measurements from hydrocarbon sensors, which have capital costs and require periodic maintenance. Also, regeneration heating and cooling requires direct-contact thermocouple measurements to determine when to apply power and when cooling is complete to initiate an adsorption cycle, respectively. However, these thermocouples can lose contact with the ACFC or create an electrical short circuit during regeneration that damages the system and/or adsorbent. For this research, a method was developed to monitor and control ACFC-ESA that eliminates the need for hydrocarbon and direct-contact temperature sensors. This method provides the ability to monitor the electrical properties of the ACFC and control adsorption cycles, regeneration cycles, and cyclic ESA based on these properties. This research is divided into five sections: 1) Characterize changes in ACFC electrical resistivity during adsorption for ACFC samples with select physical and chemical properties, 2) characterize the effect of varying temperature and applied power profiles on the ACFC regeneration energy efficiency, 3) develop and test a new method to control ACFC regeneration heating based only on electrical resistance measurements, 4) characterize and control cyclic ESA based only on electrical measurements, and 5) compare the ESA system to existing abatement systems using a life cycle assessment and a cost assessment. This method to monitor and control ESA based on the adsorbent’s electrical properties is an improvement over current methods because it provides real-time adsorbed mass during adsorption cycles resulting in improved vapor/gas recovery efficiency and does not require direct-contact temperature or hydrocarbon sensors, which periodically fail and need to be calibrated, maintained, and replaced, reducing system run time and increasing operating costs. This study provides a method to increase ACFC-ESA vapor/gas capture and recovery efficiency and reduce energy demand and vapor/gas emissions (and their corresponding health effects) to improve the sustainability of the system. The unique contributions of this research include: 1) characterization of parameters affecting ACFC electrical resistance, 2) evaluation of regeneration temperature and power profiles for their effects on regeneration energy efficiency, 3) control of regeneration cycles based on electrical properties of the ACFC, 4) control of cyclic ESA based on electrical properties of ACFC, and 5) evaluation (life cycle assessment and cost assessment) of cyclic operation with this novel method to control ACFC-ESA for vapor/gas abatement compared to typical volatile organic compound abatement systems (i.e., granular activated carbon system and regenerative thermal oxidizer)

THE SYSTEMIC REDESIGN OF MANUFACTURING SYSTEMS IN SMALL TO MEDIUM SIZED ENTERPRISES

The research problem was to develop a new approach for redesigning manufacturing systems within Small to Medium sized Enterprises (SMEs). Field observation together with literature review showed that methodologies propounded in theory were not being applied in practice. The research presents a new methodology for the systemic redesign of manufacturing systems within SMEs. The methodology consists of a four phase iterative design strategy consisting of Planning, Risk Assessment, Action and Evaluation leading to the next Planning phase. This is given a systemic basis through four perspectives: Structure; People; Process; and Technology; which frame and guide the Planning phase. Prior to this work there was no systemic approach for redesigning manufacturing systems within SMEs. These findings have been validated through the case study method and against criteria that have been identified and developed by the author. The research adopts three complementary research approaches of participant observation, action research and case study research. These are consistent with the research philosophy developed within the research frame. Participant observation is used at the outset to establish the problem domain and application considerations. Action research is used to develop a methodology that functions independent of the researcher. The final validation is carried out using case study research to evaluate the application of the methodology.CR YDOM Magnetics Ltd. and AGS Home Improvements Ltd