Automatic Algorithm Selection for Complex Simulation Problems

To select the most suitable simulation algorithm for a given task is often difficult. This is due to intricate interactions between model features, implementation details, and runtime environment, which may strongly affect the overall performance. The thesis consists of three parts. The first part surveys existing approaches to solve the algorithm selection problem and discusses techniques to analyze simulation algorithm performance.The second part introduces a software framework for automatic simulation algorithm selection, which is evaluated in the third part.Die Auswahl des passendsten Simulationsalgorithmus für eine bestimmte Aufgabe ist oftmals schwierig. Dies liegt an der komplexen Interaktion zwischen Modelleigenschaften, Implementierungsdetails und Laufzeitumgebung. Die Arbeit ist in drei Teile gegliedert. Der erste Teil befasst sich eingehend mit Vorarbeiten zur automatischen Algorithmenauswahl, sowie mit der Leistungsanalyse von Simulationsalgorithmen. Der zweite Teil der Arbeit stellt ein Rahmenwerk zur automatischen Auswahl von Simulationsalgorithmen vor, welches dann im dritten Teil evaluiert wird

Modelling large scale enterprises : A distributed simulation approach.

Distributed simulation provides an alternative solution when today's highly complicated systems including manufacturing are to be simulated. Complexities involved in implementation, the need for more expertise, high development cost and long implementation time etc. along with a lack of guidelines for developing distributed simulation, and the complexity of tools and techniques used to implement schemes, resulted in the lack of acceptance for distributed simulation among the general simulation community. In order to address some of these issues, a new approach is proposed for modelling and simulating large scale enterprises using distributed simulation. The proposed approach which includes a comprehensive methodology for distributed enterprise simulation, developed by combining activities required for traditional sequential simulation with additional activities required for distributed simulation. The thesis elaborates the additional activities required for distributed simulation in different chapters with simplified approaches for carrying out these activities. These include an approach to decide the appropriate simulation strategy (SimSS process), a simplified approach to modelling and model partitioning, a synchronization mechanism that approximately synchronizes the distributed enterprise simulation and an approach for developing distributed simulation using tools and technologies which are popular, well accepted and also cost effective. The differences between the traditional distributed simulation approaches and the proposed methodology include: partitioning of the conceptual model into logical processes before transforming them into computer simulation models, use of commercial simulation software to implement the distributed simulation, and use of cost effective and popular middleware and programming languages. Illustration of the proposed approaches focuses on distributed manufacturing applications