Peter J. Byrne

A review of Web-based simulation and supporting tools

Abstract The area of Web-based simulation (the integration of the Web with the field of simulation) (WBS) has grown since the mid-1990s. The Web itself has evolved rapidly, and current Web-related research areas include Web 2.0, service-oriented architectures and the Semantic Web. This paper gives a review of the area of WBS, exploring the advantages and disadvantages of WBS over classical simulation systems, a classification of different sub- and related-areas of WBS, an exploration of technologies that enable WBS, and the evolution of the Web in terms of its relationship to WBS.

A solution method for a two-layer sustainable supply chain distribution model

This article presents an effective solution method for a two-layer, NP-hard sustainable supply chain distribution model. A DoE-guided MOGA-II optimiser based solution method is proposed for locating a set of non-dominated solutions distributed along the Pareto frontier. The solution method allows decision-makers to prioritise the realistic solutions, while focusing on alternate transportation scenarios. The solution method has been implemented for the case of an Irish dairy processing industrys two-layer supply chain network. The DoE generates 6100 real feasible solutions after 100 generations of the MOGA-II optimiser which are then refined using statistical experimentation. As the decision-maker is presented with a choice of several distribution routes on the demand side of the two-layer network, TOPSIS is applied to rank the set of non-dominated solutions thus facilitating the selection of the best sustainable distribution route. The solution method characterises the Pareto solutions from disparate scenarios through numerical and statistical experimentations. A set of realistic routes from plants to consumers is derived and mapped which minimises total CO2 emissions and costs where it can be seen that the solution method outperforms existing solution methods.

Integrated low-carbon distribution system for the demand side of a product distribution supply chain: a DoE-guided MOPSO optimiser-based solution approach

This article contributes to distribution system literature on three inter-linked aspects viz. formulation of a novel integrated low-carbon/green distribution system for the demand side of a Supply Chain (SC) with a single product and multiple consumers, i.e. drop-off points, a novel and robust solution approach through a Design of Experiment (DoE)-guided Multiple-Objective Particle Swarm Optimisation (MOPSO) optimiser and exhaustive analysis of the solutions (i.e. prioritisation, ranking and scenario analysis). The total costs, CO2 emission and the traversed distances of the vehicles during transportation are optimised. The optimisation model for the strategic decision-making is formulated by effectively integrating the 0–1 mixed-integer programming with a green constraint based on Analytic Hierarchy Process. Due to the computationally NP-hard characteristic of the model, a systematic and technically robust DoE-guided solution approach is designed using a commercial solver – modeFRONTIER®. DoE guides the solution through the MOPSO optimiser in order to eliminate the un-realistic set of feasible and optimal solution sets. A popular multi-attribute decision-making approach, TOPSIS, evaluates the solutions found from the Pareto optimal solution space of the solver. Finally, decision-makers’ preferences are analysed for monitoring the changes in the controlling parameters with respect to the changes in the decisions. A scenario analysis of the events by considering alternative possible outcomes is also conducted. It is found that the implemented methodology successfully routes the vehicles with optimal costs and low-carbon emission thus contributing to greening the environment on the demand side of a SC network.

ISM analysis of CPFR implementation barriers

Collaborative planning, forecasting and replenishment (CPFR) as an interconnection scheme between organisations have been shown to have significant benefits. Since its inception in the 1990s, its uptake has been lower than originally predicted. This paper identifies the major barriers and their interrelationships in CPFR implementations with a focus on high-tech industries. Interpretive Structural Modelling is used with a group of CPFR experts from industry/academia and Matrice d’Impacts Croisés Multiplication Appliquée àun Classement analysis to identify the driving and dependence powers. The paper identified 45 CPFR barriers and classifies them into four categories based on expert opinion, with only 13 of these determined to be significant. The results indicate that in terms of categories, managerial barriers are a significant root cause for both process and cultural barriers and CPFR implementation difficulties. It also indicates that although the importance of information technology to launch collaborative schemes has been addressed by many scholars, technology alone is not the complete solution for successful CPFR implementation. The paper has significant practical implications for organisations as it identifies the main CPFR barriers and their causal relationships. This will help firms in the process of CPFR strategy development particularly for mitigation strategies for dominant barriers.

Design of a resilient shock absorber for disrupted supply chain networks: a shock-dampening fortification framework for mitigating excursion events

This article interweaves the widely published empirical frameworks with a new paradigm proposing stochastic dynamic decision-making tools that could be employed for capturing the trade-offs among multiple and conflicting-in-nature criteria so as to provide a design of a resilient shock absorber (RSA) for disrupted supply chain network (SCN). Modern SCNs encounter ‘excursion events’ of different kinds mainly due to uncertain and turbulent markets, catastrophes, accidents, industrial disputes/strikes in organisations, terrorism and asymmetric information. An ‘excursion event’ is an unpredictable event that effectively shuts down or has a relatively large negative impact on the performance of at least one member of a system for a relatively long amount of time. In this article, design of an analytical framework has been conceptualised that allows an SCN to avoid propagating the ill effects of the ‘excursion events’ further and maintains the network at a desired equilibrium level. A broad analytical view of econophysics has been conceptualised using the definition of a ‘system’ from physics. An example derived from the 9/11 case has been delineated in order to illustrate the efficacy of the proposed design. The devised RSA facilitates the assessment of resiliency strategies for SCNs prone to excursion events that are characterised by low probability of occurrence and high impact. The shock-dampening fortification framework also enables practitioners to identify and assess quantitatively the islands of the excursion events in SCN.

Discrete-event simulation for evaluating virtual organizations

Outsourcing is a major driver in the growth of virtual organizations (VOs) in the manufacturing domain. These outsourcing networks can be classified as VOs as they are created from different organizational entities for a specific purpose and exist for a specified period of time. This paper proposes the use of discrete event simulation (DES) as a means of evaluating proposed VO configurations within the request for quotation (RFQ) process. The work presented is targeted at manufacturing-based VOs that are created to carry out specific manufacturing tasks as outlined in an RFQ, rather than more general project-based VOs that are formed to carry out work within a less defined structure. Data from an existing virtual breeding environment (VBE), obtained during field research into outsourcing networks, is used to illustrate the use of DES to support VO creation. As DES requires a high level of skill to use, the design of an easy-to-use web-based application with an embedded simulation engine is described.

The CACTOS Vision of Context-Aware Cloud Topology Optimization and Simulation

Recent advances in hardware development coupled with the rapid adoption and broad applicability of cloud computing have introduced widespread heterogeneity in data centers, significantly complicating the management of cloud applications and data center resources. This paper presents the CACTOS approach to cloud infrastructure automation and optimization, which addresses heterogeneity through a combination of in-depth analysis of application behavior with insights from commercial cloud providers. The aim of the approach is threefold: to model applications and data center resources, to simulate applications and resources for planning and operation, and to optimize application deployment and resource use in an autonomic manner. The approach is based on case studies from the areas of business analytics, enterprise applications, and scientific computing.

Sustainable supply chain design: capturing dynamic input factors

Across the European Economic Area (EEA) more goods are being transported over longer distances more frequently than ever before. As a result, Greenhouse Gas emissions from transport increased overall by 28% between 1990 and 2006 for the 32 countries in the EEA. With incoming Kyoto regulations, and opinion resistant to heavy freight traffic, efficient freight transport has become a growing concern. This paper will document the tools already used in environmental supply chain (SC) analysis and investigate the potential use of discrete event simulation (DES) as a method of capturing the dynamic nature of modern SC design and operation. The paper reviews and analyses the use of quantitative analysis for supporting SC decision makers in choosing the most environmentally friendly SC design. This is done through the development and use of a DES model, which, through the capture of dynamic input factors, illustrates the economic versus environmental trade-offs of alternative SC designs.

A framework for Collaborative Planning, Forecasting and Replenishment (CPFR): State of the Art

Purpose – Although many papers purport the significant value attributable to supply chain performance from the use of Collaborative Planning, Forecasting and Replenishment (CPFR), the question of “what are the main constructs and efficient framework for successful implementation of CPFR?” remains largely unanswered. This question will be addressed by identifying and analysing the main constructs for successful implementation of CPFR. The purpose of this paper is to attempt first to seek answers to this question. Second, to review the scope and value of CPFR using a devised state-of-the-art taxonomy for the classification of selected bibliographical references and third, to develop a conceptual framework by identifying areas which need more research. Design/methodology/approach – The method underlying this paper followed the steps of a systematic literature review process outlined by Soni and Kodali (2011). The review is based on a total of 93 papers published from 1998 to 2013 on CPFR. Findings – Four mai...

A simulation based supply partner selection decision support tool for service provision in Dell

Partner selection is an important aspect of all outsourcing processes. Traditional partner selection typically involves steps to determine the criteria for outsourcing, followed by a qualification of potential suppliers and concluding with a final selection of partner(s). Reverse auctions (RAs) have widely been used for partner selection in recent times. However, RAs, although proven successful in initial price reduction strategies for product and service provision, can suffer from reduced effectiveness as the number of executions increases. This paper illustrates Dells experience of such diminishing returns for its outsourced after sales product repair service and presents the development of a new partner selection methodology, which incorporates a new process improvement stage to be executed in combination with the final selection phase. This new methodology is underpinned by the development of a computer based simulation supply partner selection decision support tool for service provision. The paper highlights the significant additional cost saving benefits and improvement in service achievable through the use of advanced simulation based decision supports.