An object-oriented simulation modeling environment, AgvTalk, is presented to provide flexible modeling capabilities for simulation of many alternative AGV systems. The hierarchical features and modularity of AgvTalk create possibilities for the extension and reuse of simulation object components. Also, detailed behavior of each object in the AGV system can be modeled easily and exactly in AgvTalk because there are no limiting modeling constructs. The modeling capabilities of AgvTalk is demonstrated by designing and simulating a conceptually different configuration of AGV systems, known as, the tandem configuration. Between the tandem and conventional AGV systems, the characteristics and design methodology in AgvTalk are described. Also, simulations between two systems are compared with AgvTalk in the job shop environment.

Two-dimensional cutting stock problem is to find a waste-minimizing method of cutting a single rectangular plane into a number of smaller pieces of known dimensions. In practice, besides wastes, setup cost taken during adjusting is of an important concern. We suggest 2-phased guillotine cutting method as a solution to the problem which minimize wastes and setup costs. Also, in order to reduce the computing time we apply techniques of discretization, cutoff, median. Experimental results show good performance of our algorithm.

In this paper, a threshold policy is considered for the Markovian queueing system with server vacations. The threshold policy considered in this paper has the following form: "when the number of customers present in the system increases to N, the server is turned on and serves customers until the system becomes empty". In this paper, we show how the finite capacity or finite population queueing system under a threshold policy can be modeled by the stochastic Petri net. The performance evaluation of the model is carried out using the software called "SPNP". Some examples are also presented in which it is shown that how the optimal threshold policies can be obtained under a linear cost structure.

A special purpose automated storage and retrieval system is developed in which information media such as compact disc or video tapes can be stored. Hardware system includes rack, stacker crane with robot arm, conveyor, and bar code reader. Software system includes database for address management, user interface for quick scanning of information media by displaying moving image, and algorithms for selecting the closest open location. Such system is widely applicable to CD library or broadcasting station in the forthcoming information age. In this paper we present detailed procedure and tools that are used in designing and implementing such a special AS/R system.

Nowadays, various sides such as political, economical, technical and social sides of the companies' environment are changed rapidly. Such changes could provide a risk on one hand and a good chance on the other hand to the companies. Only one that has quick self-adaption can survive such kinds of challenges. Thus, from now on, profitable survival of a company depends on how fast they can adapt for the changes. Therefore it is introduced here the production method of a new concept for solving many problems which exist in the present production and manufacture.