Discrete Event Simulation Technology Research Articles

High-level fuel fabrication facility designs from discrete-event simulation

Like other industrial processes, the production of metallic nuclear fuels (MNF) requires that fabrication facilities be able to reliably meet production demands, operate efficiently, and adhere to federal and local safety regulations. In turn, the set of design variables employed by such a facility, such as operations policies, infrastructure and machinery purchased, and the type and number of staff hired, directly impact a facility’s ability to satisfy these goals. Therefore, facility designers must carefully determine which set of design variable values optimally satisfies these constraints. In this paper, we explore how values for these high-level design variables, namely hiring requirements, can be determined in the context of nuclear fuel manufacturing through the coupling of physics-based and discrete-event simulation technologies. Using the Versatile Test Reactor (VTR) program as a case study, we demonstrate how SCALE and MCNP nuclear physics model outputs can be integrated into ExtendSim discrete-event simulation (DES) models of the fuel fabrication process to determine the optimal number of staff hired to ensure fuel production goals are met, operations comply with effective dose limit regulations, and overall project costs are reduced.

Research on Virtual Simulation of Modern Residential Buildings Based on BIM and Two-Dimensional Code Technology

Natural environment, construction, transportation and other factors have a great impact on the construction process of modern residential buildings. The interaction of these factors is the reason for the uncertainty of concrete dam pouring environment, but the traditional method is not suitable for this uncertainty. Therefore, discrete event simulation (DES) is widely used in construction simulation, rather than actual construction. This is because most simulation models are created by professionals and require manpower and material resources. Even if there is a small change in the simulation process, it should be introduced into the simulation model to adjust in order to adapt to the new environment. With the help of DES technology based on BIM to construct the framework of concrete dam, this paper fully studies the relationship between concrete structure and BIM and the two-dimensional code technology, solves the problem of information expression, and plays an important role in the application of simulation technology in the research of construction progress and reasonable design of construction scheme.

Development of a central order processing system for optimizing demand-driven textile supply chains: a real case based simulation study

Nowadays, the demand of small-series production and quick response become more and more important in textile supply chains. To meet the increasing trend of customization in garment production, forecast based supply chain model is not suitable any more. Demand-driven garment supply chain is developed and employed more and more. However, there are still many defects in current model for demand-driven supply chains, e.g. long lead time, low efficiency etc. Therefore, in this study we proposed a new collaborative model with central order processing system (COPS) to optimize current demand-driven garment supply chain and improve multiple supply chain performances. Common and important supply chain collaboration strategies, including resource sharing, information sharing, joint-decision making and profit sharing, were merged into this system. Discrete-event simulation technology was utilized to experiment and evaluate the new collaborative model under different conditions based on a real case in France. Multiple key performance indicators (KPIs) were examined for the whole supply chain and also for individual companies. Based on the simulation experiment results, we found that new proposed collaborative model gain improvements in all examined KPIs. New model with COPS performed better under high workload condition than under low workload condition. It can not only increase overall profit level of the whole supply chain but also individual profit level of each company.

Simulation-based Planning of a Kind of Complex Product General Assembly Line

The assembly process of a kind of complex product consists of many parallel assembly workstations with re-entrant process and resource constraints. The traditional production experience and manual computing has not been able to provide a convincing reference for new production line planning considering capacity analysis, resources allocation and optimization. In this paper, by analyzing the characteristics of this category production line, an assembly system planning method combined with discrete event simulation technology for the product is described to verify and improve the planning scheme. Several scenarios are experimented and compared based on the analysis of line throughput, cycle time, bottlenecks and work-in-process control strategy. The simulation-based planning method provides sufficient data support for design decision-making of the new production line.

The Simulation of the Time Slot CSMA/CD Protocol Based on P-Persistent Exponential Backoff Algorithm

The time slot CSMA/CD protocol model based on the discrete event simulation technology is established in the article, and the object-oriented simulation technology is adopted to implement the simulation software, and the influences of the messaging probabilities on the network performance are analyzed under different loads, and the result shows that to enhance the comprehensive performance parameter of the network, the influences of the P value under different loads must be comprehensively considered.

An optimal integrated production planning and scheduling method for bell-type anneal shop

A two-stage mathematic programming model is established in this paper for the integrated production planning and scheduling problem in bell-type anneal shop. The stage I aims at the minimized heating time of each base to optimize the furnace-charging combination. The stage II based on the combined anneal plan is to obtain an optimized resource scheduling solution in order to minimize the resource free ratio. In this stage, a discrete event simulation technology based on SystemC platform and an adaptive genetic algorithm are used. Finally, the simulation experiments using practical production data show the proposed two-stage integrated method is effective and reliable.

Trends in Discrete Event Simulation

Discrete event simulation technologies have been up and down as global manufacturing industries went through radical changes. The changes have created new problems, challenges and opportunities to the discrete event simulation. On manufacturing applications, it is no longer an isolated model but the distributed modeling and simulation along the supply chain. In order to study the hybrid manufacturing systems, it is critical to have capability to model human performance with different level of skills and under various working conditions. On service applications, the most critical part is to model knowledge workers and their decision making process. This paper reviews the discrete event simulation technologies; discusses challenges and opportunities presented by both global manufacturing and the knowledge economy.

Developing simulation as a desktop resource

While discrete event simulation technology holds tremendous promise and has a strong and established background, manufacturing industry has been less than successful in the implementation of simulation as a decision support tool. This paper reports on research into developing simulation into a sustainable desktop resource to be used continuously by various manufacturing personnel as a decision support tool. A case study approach was used to carry out the research. The manufacturing system used was a medium-sized facility that could be categorized as a batch flow-shop that produces a large range of products. The simulation software was developed using the object-oriented simulation package eM-Plant®. In designing the simulation model, emphasis was placed on integrating with the manufacturing company's information systems and reducing the resources required to maintain the software. The simulation software was successfully used for both strategic and short-term planning. However, as a sustainable resource within the company, the simulation model developed was only partially successful. The main difficulties identified were in model maintenance and data collection. The main conclusions of the paper are that: (1) simulation places specific requirements on information systems which need to be taken into consideration if simulation is to be successfully implemented as a desktop resource; (2) improvements in simulation software are required to reduce model maintenance resource requirements; and (3) research on socio-technical issues into simulation use within manufacturing is required.

特集 シミュレーション技術の新展開 離散型シミュレーション技術の現状と動向

特集 シミュレーション技術の新展開 離散型シミュレーション技術の現状と動向

A case against event-driven simulation for digital system design

The author argues that the electronic design community too often tries to apply discrete event simulation technology, such as VHDL, to applications for which it is ill-suited. In particular he considers the simulation of synchronous digital designs, and reports two orders of magnitude speed improvement by using compiled simulation instead. The basic design of a simple compiled simulator is outlined. >