A simulation framework for the performance assessment of shop-floor control systems

The authors discuss the concept and design criteria for a framework that facilitates the performance assessment of shop-floo control systems. Their basic concept includes a simulation model that emulates the shop floo of a wafer fab, sends information to the control system, and eceives information back from the control system. The shop-floo control system is realized as a separate module that interfaces to the simulator via a data layer that contains the current shop-floo status and the control information generated by the controller. The authors provide detailed information on how the simulation model and shop-floo control system communicate and how each system triggers events in the other system. They show how this framework supports the performance assessment of the shop-floo control system under consideration. They also present a prototype of the framework currently implemented in the course of the SRC/International Sematech FORCe project "Scheduling of Semiconductor Wafer Fabrication Facilities.

Yüksek seviyeli mimari (HLA) temelli dağıtık imalat benzetimi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Benzetim, bir karar verme aracı olarak her zaman kullanılagelmiştir. Benzetimin en çok kullanıldığı alanların başında imalat gelmektedir. Ancak geleneksel benzetim teknikleri tek başına karmaşık dağıtık imalat problemlerini modellemeye yetmemektedir. Son yıllarda imalat süreci oldukça karmaşık hale geldiğinden ve çoğu zaman dağıtık ortamlarda gerçekleştirildiğinden dağıtık imalat benzetimi modellerine ihtiyaç duyulmaktadır. Farklı benzetim modellerini bir araya getirerek bilgi alışverişini gerçekleştirecek ortak mimariye olan ihtiyaç, başlangıçta askeri alanlarda ortaya çıkmıştır. Benzer ihtiyac, dağıtık imalat benzetiminde de hissedilmektedir. Böyle bir mimari benzetim modellerinin yeniden kullanılabilirlik ve karşılıklı işleyebilirlik özelliklerine sahip olmasını sağlayabilmelidir. Bununla birlikte, bilgi alışverişinde bulunacak olan benzetim modelleri farklı platformlarda, farklı ticari benzetim paketleriyle veya farklı uygulama yazılımları ile modellenmiş olabilmektedir. HLA, bu tür problemleri çözmekte kullanılabilecek dağıtık benzetim mimarisidir. Amerikan Savunma Bakanlığı tarafından askeri benzetim sistemlerinde kullanılmak üzere 1995'lerden itibaren geliştirilen bu mimari, imalatta ve diğer sivil alanlarda da uygulanmaktadır. 2000 yılında IEEE tarafından 1516 kodu ile dağıtık benzetim standardı olarak kabul edilmesiyle sivil alanlarda kullanımı yaygınlaşmıştır.Bu çalışmada HLA temelli dağıtık imalat benzetimi ele alınmıştır. Dağıtık imalat benzetiminin yararları, HLA'nın imalatta kullanım gerekçesi, HLA temelli dağıtık imalat benzetimi geliştirmek için neler yapılması gerektiği açıklanmıştır. Çeşitli HLA temelli dağıtık imalat tasarım örnekleri verilmiştir. Örnek bir uygulama ile HLA'nın pratik olarak dağıtık imalat benzetiminde nasıl uygulandığı ortaya konulmuştur.Manufacturing is one of the areas where simulation is used more widely as a decision making tool. But traditional simulation techniques are not capable to simulate complex manufacturing systems. Since manufacturing processes became more complex and mostly performed in distributed environments, distributed manufacturing simulation models are needed. So, a common framework is required to integrate and exchange information of different manufacturing simulation models. The framework should have the capability of reusability and interoperability since simulation models could be modeled at different environments with different application programming languages. HLA can meet all of the requirements mentioned above. HLA was developed by American Department of Defense (DoD) since 1995 for military simulations, and after it was accepted as an IEEE standart (No:1516) in year 2000, HLA is being used not only for military simulations but also for civil applications.In this study HLA based distributed manufacturing simulation is examined. The benefits of distributed manufacturing simulation, reasons why HLA is used in manufacturing, what sould be done in order to develop HLA based distributed manufacturing simulation is explained in the study. It will also be put forward how HLA is implemented practically in distributed manufacturing simulation through a given scenario

An Adaptive Simulation-based Decision-Making Framework for Small and Medium sized Enterprises

Abstract The rapid development of key mobile technology supporting the ‘Internet of Things’, such as 3G, Radio Frequency Identification (RFID), and Zigbee etc. and the advanced decision making methods have improved the Decision-Making System (DMS) significantly in the last decade. Advanced wireless technology can provide a real-time data collection to support DMS and the effective decision making techniques based on the real-time data can improve Supply Chain (SC) efficiency. However, it is difficult for Small and Medium sized Enterprises (SMEs) to effectively adopt this technology because of the complexity of technology and methods, and the limited resources of SMEs. Consequently, a suitable DMS which can support effective decision making is required in the operation of SMEs in SCs. This thesis conducts research on developing an adaptive simulation-based DMS for SMEs in the manufacturing sector. This research is to help and support SMEs to improve their competitiveness by reducing costs, and reacting responsively, rapidly and effectively to the demands of customers. An adaptive developed framework is able to answer flexible ‘what-if’ questions by finding, optimising and comparing solutions under the different scenarios for supporting SME-managers to make efficient and effective decisions and more customer-driven enterprises. The proposed framework consists of simulation blocks separated by data filter and convert layers. A simulation block may include cell simulators, optimisation blocks, and databases. A cell simulator is able to provide an initial solution under a special scenario. An optimisation block is able to output a group of optimum solutions based on the initial solution for decision makers. A two-phase optimisation algorithm integrated Conflicted Key Points Optimisation (CKPO) and Dispatching Optimisation Algorithm (DOA) is proposed for the condition of Jm|STsi,b with Lot-Streaming (LS). The feature of the integrated optimisation algorithm is demonstrated using a UK-based manufacture case study. Each simulation block is a relatively independent unit separated by the relevant data layers. Thus SMEs are able to design their simulation blocks according to their requirements and constraints, such as small budgets, limited professional staff, etc. A simulation block can communicate to the relative simulation block by the relevant data filter and convert layers and this constructs a communication and information network to support DMSs of Supply Chains (SCs). Two case studies have been conducted to validate the proposed simulation framework. An SME which produces gifts in a SC is adopted to validate the Make To Stock (MTS) production strategy by a developed stock-driven simulation-based DMS. A schedule-driven simulation-based DMS is implemented for a UK-based manufacturing case study using the Make To Order (MTO) production strategy. The two simulation-based DMSs are able to provide various data to support management decision making depending on different scenarios

A Simulation Framework for the Performance Assessment of Shop-Floor Control Systems

The authors discuss the concept and design criteria for a framework that facilitates the performance assessment of shop-floor control systems. Their basic concept includes a simulation model that emulates the shop floor of a wafer fab, sends information to the control system, and receives information back from the control system. The shop-floor control system is realized as a separate module that interfaces to the simulator via a data layer that contains the current shop-floor status and the control information generated by the controller. The authors provide detailed information on how the simulation model and shop-floor control system communicate and how each system triggers events in the other system. They show how this framework supports the performance assessment of the shop-floor control system under consideration. They also present a prototype of the framework currently implemented in the course of the SRC/International Sematech FORCe project “Scheduling o