Facilitating the analysis of a UK national blood service supply chain using distributed simulation

In an attempt to investigate blood unit ordering policies, researchers have created a discrete-event model of the UK National Blood Service (NBS) supply chain in the Southampton area of the UK. The model has been created using Simul8, a commercial-off-the-shelf discrete-event simulation package (CSP). However, as more hospitals were added to the model, it was discovered that the length of time needed to perform a single simulation severely increased. It has been claimed that distributed simulation, a technique that uses the resources of many computers to execute a simulation model, can reduce simulation runtime. Further, an emerging standardized approach exists that supports distributed simulation with CSPs. These CSP Interoperability (CSPI) standards are compatible with the IEEE 1516 standard The High Level Architecture, the defacto interoperability standard for distributed simulation. To investigate if distributed simulation can reduce the execution time of NBS supply chain simulation, this paper presents experiences of creating a distributed version of the CSP Simul8 according to the CSPI/HLA standards. It shows that the distributed version of the simulation does indeed run faster when the model reaches a certain size. Further, we argue that understanding the relationship of model features is key to performance. This is illustrated by experimentation with two different protocols implementations (using Time Advance Request (TAR) and Next Event Request (NER)). Our contribution is therefore the demonstration that distributed simulation is a useful technique in the timely execution of supply chains of this type and that careful analysis of model features can further increase performance

Gaining insight into business networks: A simulation based support environment to improve process orchestration

In today's world, organizations are becoming increasingly interested in using business networks as a means to adapt to the ever-changing environment to increase their performance level. As a result, the focus of efforts to improve the performance of organizations has shifted from organizational level to the inter-organizational level. An important challenge organizations need to meet in a business network is efficient and reliable business process orchestrations with their partners. Limited visibility of business process orchestrations in the network is one reason. In the research presented in this thesis, we examined process orchestration issues in business networks using the US Department of Defence business network as a case study. From the case study we developed requirements for a support environment to improve the efficiency and reliability of process orchestration in business networks. Based on the requirements, we developed a simulation based support environment that can be used to assist organizations to design an efficient and reliable process orchestration. The simulation based support environment consists of a methodology, which guides the process of improving process orchestration, and a software tool, which assists the development of simulation models. The support environment was tested in an experimental setting. Experts in the field evaluated the usefulness of the support environment. The experiments and expert evaluation show that the support environment can be used to support the process of improving the efficiency and reliability of process orchestration in business networks.Technology, Policy and Managemen