ESNEK ÜRETİM SİSTEMLERİNİN SÜREÇ TABANLI PETRİ AĞLARI İLE MODELLENMESİ

Abstract

Flexible manufacturing systems are seen as a new competitive force among contemporary manufacturing systems. This system, however, offers many advantages to the manufacturer, have led to highly complex analysis methods at the planning and modeling stages. The modeling of a flexible manufacturing system discussed in the study is based on the idea of combining two different approaches, namely object-oriented modeling and process-based Petri Nets. The object-oriented modeling method can be used at the unit level, based on the fact that processes can be added to and subtracted from the main line. At this point, it is aimed to incorporate the re-configurability feature into the flexible manufacturing system model. Sub-processes to be used in any flexible manufacturing are grouped into classes and common models are assigned to sub-processes. While modeling the processes, process-based Petri Nets are used.

After a comprehensive literature review on flexible manufacturing systems and Petri Nets, we discuss how these two approaches could be combined and propose a new approach by synchronizing the object-oriented modeling technique with the process- based Petri Nets. This proposed idea involves the steps necessary to model a flexible manufacturing system. Two notations have been utilized to show that these steps can be implemented, with “1AXYZ object classification notation” and “101 notation of process-based Petri Nets”. According to the 1AXYZ object classification notation, all processes are combined under the operations and individualized by coding. Hence, each process is defined by a unique code number. In this way, every process that will be added to the system is known beforehand. At the same time, with this notation, the system is given the appearance of modular sub-elements and the ability to re-configure the model designing process has been introduced. Therefore, it is aimed to increase the flexibility of the model.

The 101 notation of process-based Petri Nets has also created a common notation rationale for processes separated by classes and this logic is used within two stages. The first of these is the 101 notation display method of process-based Petri Nets at the main line level and the other is the 101 notation of process-based Petri nets at the station level. In this respect, a model that introduces the manufacturing process in the modeling stage, as well as the design of the processes performed at the stations’ level of the factory are shown in the manufacturing model. It was later suggested that these two representations could be combined in a style adaptable to flexible manufacturing systems so that the designer could model the system in such a way as well. These advanced methods have been adapted to a flexible manufacturing system from the literature. Difficulties encountered during the modeling phase are highlight together with the suggested solutions for these and the future studies.