Using a Discrete-event Simulation Model for Efficient Operation of Tunnel Boring Machines Mohammad Mahdi Farshchian, Gholamreza Heravi

A tunnel boring machine (TBM) is the primary resource in a tunnel construction project and generally its advance rate is equal to the performance rate of the whole project. Regarding previous studies, the utilization factor of TBMs is approximately 50% most of the time. The process of repair and maintenance of various parts of the machine and the logistic equipment takes 50% of the time. This case study aims to simulate the whole process of TBM tunneling in Ahwas subway project and find out how different scenarios of repair and maintenance can affect the utilization factor of the TBM. The model is developed using discrete-event simulation (DES) method.
» Lire plus

A Hybrid Simulation Approach to Dynamic Multi-Skilled Workforce Planning of Production Line Yuan Feng, Wenhui Fan, Tsinghua University. Winter Simulation Conference, 2014.

Workers cross-trained with multiple tasks can improve the workforce flexibility for the plant to handle
variations in workload. Therefore, it is necessary to study the dynamic multi-skilled workforce planning
problem of production line with the application of cross-training method.
» Lire plus

Iterative Simulation and Optimization Approach for Job Shop Scheduling Ketki Kulkarni, Jayendran Venkateswaran, Indian Institute of Technology Bombay. Winter Simulation Conference, 2014.

In this paper, we present an iterative scheme integrating simulation with an optimization model, for solving
complex problems, viz., job shop scheduling. The classical job shop scheduling problem which is NP-Hard,
has often been modelled as Mixed-Integer Programming (MIP) model and solved using exact algorithms (for
example, branch-and-bound and branch-and-cut) or using meta-heuristics (for example, Genetic Algorithm,
Particle Swarm Optimization and Simulated Annealing).
» Lire plus

An Online Simulation To Link Asset Condition Monitoring And Operations Decisions In Through-Life Engineering Services Benny Tjahjono, Evandro Leonardo Silva Teixeira, Sadek Crisóstomo Absi Alfaro, Proceedings of the 2013 Winter Simulation Conference

This paper presents an online simulation framework that can be used to support operational decisions within the context of Through-life Engineering Services. Acting as a closed-loop feedback control mechanism, the simulation model is physically coupled to the assets and will be triggered and automatically executed to assess a set of operational decisions related to maintenance scheduling, resource allocation, spare parts inventory etc. Experimental cases comparing the online simulation against the traditional approach will also be presented. The outcomes have demonstrated the prospects of the framework in enabling more effective/efficient operations of engineering services leading to high assets availability and reduced through-life costs.
» Lire plus

A Detailed Model For a High-Mix Low-Volume ASIC FAB Mike Gissrau, Oliver Rose. Proceedings of the 2011 Winter Simulation Conference

Looking for new improvement options such as new dispatching rules of an existing semiconductor fabrication facility, a detailed model is indispensable to check the data quality as well as detecting main influences of the facility and finally testing the new optimization approaches.
» Lire plus

A Generic Operational Simulation for Early Design Civil Unmanned Aerial Vehicles Benjamin Schumann, Jim Scanlan (School of Engineering Sciences University of Southampton); Kenji Takeda (Microsoft Research). Proceedings of the SIMUL 2011: The Third International Conference on Advances in System Simulation

Contemporary aerospace programmes often suffer from large cost overruns, delivery delays and inferior product quality. This is caused in part by poor predictive quality of the early design phase processes with regards to the operational environment of a product. This paper develops the idea of a generic operational simulation that can help designers to rigorously analyse and test their early product concepts. The simulation focusses on civil Unmanned Air Vehicle products and missions to keep the scope of work tractable.
» Lire plus

IRS POST-FILING PROCESSES SIMULATION MODELING: A COMPARISON OF DES WITH ECONOMETRIC MICROSIMULATION IN TAX ADMINISTRATION Arnold Greenland, Erica Layne Morrison, David Connors, John L. Guyton, Michael Sebastiani, 2007 Winter Simulation Conference (WSC’07), Washington D.C., December 9-12, 2007

IRS Office of Research Headquarters measures and models taxpayer burden, defined as expenditures of time and money by taxpayers to comply with the federal tax system. In this research activity, IRS created two microsimulation models using econometric techniques to enable the Service to produce annual estimates of taxpayer compliance burden for individual and small business populations. Additionally, a Discrete Event Simulation (DES) model was developed to represent taxpayer activities and IRS administration in postfiling processes.
» Lire plus

AnyLogic 4.0: Simulating Hybrid Systems with Extended UML-RT Andrei Borshchev. Simulation News Europe, No. 31 April 2001, pp 15-16

We outline a modelling approach aimed to capture sophisticated interdependencies of discrete and continuous behaviors in hybrid systems. The approach is essentially a hybrid extension of widely recognized object-oriented languages UML and UML-RT. It is fully supported by a new simulation tool AnyLogic 4.0 from Experimental Object Technologies.
» Lire plus

Distributed simulation of hybrid systems with AnyLogic and HLA Andrei Borshchev, Yuri Karpov, and Vladimir Kharitonov. Future Generation Computer Systems Volume 18, Issue 6 (May 2002)

A large class of systems being developed has both continuous time and discrete time behavior. In fact, any system that interacts with physical world falls in that class. Chemical, Automotive, Military, Aerospace are areas most frequently mentioned in this respect. To model such systems successfully and to get accurate and reliable results from simulation experiments one needs an executable language naturally describing hybrid behavior, and a simulation engine capable of simulating discrete events interleaved with continuous time processes. Additional problems arise with simulating hybrid systems in a distributed environment.
» Lire plus

Decision Support Tool — Supply Chain Christian Wartha, Momtchil Peev, Andrei Borshchev, and Alexei Filippov. 2002 Winter Simulation Conference (WSC’02), December 8-11, 2002, San Diego, California, USA

We present a currently developed Decision Support Tool - Supply Chain (DST-SC). This is specialized domain oriented tool, which is an extension of the general purpose, UML-RT Hybrid Simulation kernel of AnyLogic by XJ Technologies. DST-SC allows high degree of flexibility with respect to the supply chain functionality being modeled, has the ability to handle large complex problems, and offers highly reusable model components, offering at the same time ease of use by non-experts in simulation.
» Lire plus