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Simulation in Produktion und Logistik

Karlsruhe (TH) soll sich vorrangig der Integration technischer, organisatorischer und personalorientierter Aspekte bei der Modellierung und Simulation von Produktionsund Logistiksystemen widmen. Damit soll aufgezeigt werden, dass Simulationsverfahren in der Lage sind, vielfaltige Aspekte des technischen Managements gleichermasen modellhaft abzubilden und auf der Basis einer multikriteriellen Zielsetzung zu bewerten. Dies hat Auswirkungen auf die Datenhaltung und die Modellierungstechnik, beruhrt aber auch Fragen der Verifikation und Validierung von Simulationsverfahren und der mit ihnen erstellten Modelle. Wie schon bei den vorangegangenen ASIM-Fachtagungen sollen Forschung, Entwicklung und industrielle Nutzung gleichermasen diskutiert werden. Es werden aktuelle Forschungsergebnisse wie auch Best-Practice-Beispiele der Simulation im betrieblichen Alltag vorgestellt. Somit erhalten Teilnehmer ohne Simulationserfahrung einen Uberblick uber Moglichkeiten und Grenzen der Simulation, wahrend erfahrene Anwender die Tagung zum Erfahrungsaustausch nutzen und neue Angebote begutachten konnen.

Neutral template libraries for efficient distributed simulation within a manufacturing system engineering platform

The MISSION project develops an environment for integrated applications of simulation tools which can be offered by different vendors. The template library supports the generation of models from the view of the application instead of simulation tool features. The selection of simulation tools applied is performed with the mostly completed, but still neutral model. The template library is a reservoir of neutral re-usable elements incorporating their major attributes, and referencing to implementations of these models in different simulation tools. Within the manufacturing system engineering (MSE) process, the template library is mainly used as a flexible knowledge base. For this purpose, attributes can be defined depending on the design agents applied. Some attributes are predefined according to the requirements of the MISSION modelling platform (MMP) or according to available user requirements. The user has the chance to add templates and attributes of templates. Furthermore, the user can use objects of these templates within the MSE process. Concerning the simulation process, the template library contains for each application template a reference to simulation models. The simulation model implements the content of the template. The paper presents the template library approach and a short introduction to the MISSION platform.

A new procedure model for verification and validation in production and logistics simulation

Verification & validation of simulation models and results has been strongly investigated in the context of defence applications. Significantly less substantial work can be found for applications for production and logistics, which is surprising when taking into account the massive impact that wrong or inadequate simulation results can have on strategic and investment-related decisions for large production and logistics systems. The authors have, therefore, founded an expert group for this specific topic in the year 2003, which has analysed the existing material and then developed proposals for definitions, overviews on existing V&V techniques, practical hints for the documentation of the procedural steps within a simulation study, and a specific procedure model for V&V in the context of simulation for production and logistics. The results of this working group are available as a textbook, in German. This paper summarises major results.

Distributed modelling and simulation of supply chains

The behaviour of supply chains, especially those in which several enterprises are involved, is often difficult to predict. For the analysis of such systems, which cannot be evaluated by analytical models, discrete event simulation is an adequate technology. The competence of the local engineers about the single chain elements has to be incorporated into the simulation models. This can be done best by establishing local models, representing the local section of the supply chain. Up to now, integrating such local models into one complete model was time consuming and error prone. Even more critical, local maintenance of partial models was inhibited. A new approach solves this problem, exploiting the advantages of distributed simulation. Furthermore, this approach provides encapsulation, if supply chain partners do not wish to publish details of their node to other partners. The interfacing description is based on the High Level Architecture (HLA) and generates Extensible Markup Language (XML) files, which provide a specification of each supply chain node and its interfaces.

Reference models for supply chain design and configuration

Today more and more essential processes are conducted across enterprise borders, inducing additional challenges in terms of different languages, process types and ontology. Business process modelling (BPM) and Simulation are well-understood methods to analyze and optimize the processes within an enterprise. However, they can also be used for cross-organizational application, especially if they are combined with reference structures. This paper explains techniques which support cross-enterprise design and configuration based on Reference Models. Thereby, different approaches such as SCOR, the integrated enterprise modelling (IEM) and a specific distributed simulation method are used and integrated into a consistent reference model approach. The application of this approach is illustrated with different projects which each focus on a specific aspect of the supply chain design and configuration

The MISSION Project

Supply chains bring specific tasks to simulation. As long as the simulation is performed at a very high level, the simulation can be done in the traditional way. But, for detailed simulation the competence from the single chain elements has to be incorporated into the models. This can be done best by the local engineers. Up to now, integrating local models into one complete model was time consuming and error-prone. Even more critical, local maintenance of partial models was inhibited. A new approach solves this problem, and furthermore provides encapsulation, if supply chain partners do not wish to publish details of their node to other partners. The interfacing description generates XML files, which provide a specification of each supply chain node and its interfaces, too.

Integration of Factory Planning and ERP/MES Systems: Adaptive Simulation Models

The purpose of this paper is to demonstrate the approach of a scalable, flexible and adaptive simulation model used in factory planning on the basis of existing ERP and MES data. The dynamic simulation model was developed to validate and verify the changes of the production yield during factory planning and restructuring in the shop floor. This includes machinery relocation and ramp-up, new product phase-in, product portfolio changes and new product qualification processes. The objective is to enable an industrial engineer without simulation knowledge and experience to perform the simulations. Moreover, the model facilitates an analysis of the results for different scenarios, using the actual data from the ERP and MES systems.

An approach for increasing flexibility in green supply chains driven by simulation

Flexibility is a relevant topic in the field of green supply chains (GSC), as disturbances lead to additional transport and storage, frequently aggravated by energy-consuming air conditioning requirements. This paper discusses how simulation can support to establish flexible GSCs with specific focus on decreasing CO2 and energy consumption. For this purpose, the term flexibility is structured into categories, and methodological approaches driven by simulation in supply chains are studied. Flexibility requirements in the context of a GSC are analyzed and potential support derived for increasing this flexibility, gained by a join of simulation techniques, data models and morphological characteristics of flexibility. An approach for systematic flexibility analysis is presented on the grounds of a data mart that represents both internal and external factors influencing GSC scenarios.

A Success Story: Manufacturing Execution System Implementation

The paper describes project procedures of a successful implementation for manufacturing execution systems on a real case. It illustrates interoperability barriers arisen during the project and how they are handled. The focus is on aspects of arising issues of organisational interoperability between IT-vendor and its customer (the user). An enterprise model was used as the major tool for the description of the processes but also in the communication between user and IT vendor. This enterprise model has also guided the implementation of the IT system. The project has been finished successfully end of 2009.

Semantic Web Framework for Rule-Based Generation of Knowledge and Simulation of Manufacturing Systems

The development of new products and manufacturing systems is usually performed in the form of projects. Frequently, the conduction of the project takes more time than planned due to inconsistency, incompleteness, and redundancy of data, which delays other project activities influencing the start of production (SOP). This paper proposes a semantic Web framework for cooperation and interoperability within product design and manufacturing engineering projects. Data and knowledge within the manufacturing domain are modelled within ontologies applying rule-based mapping. The framework facilitates the generation of new knowledge through rule based inference that enriches the ontology. This enables a high-level model completeness in the early phase of product design and manufacturing system development, which is a basic prerequisite for the realisation of a proper simulation study and analysis. The simulation results can be integrated into the ontologies as a knowledge that additionally extends the ontology.