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Applied Computer Science Volume 4, Number 1, 2008

DESIGN OF EQUIVALENT ONE-TIME MODEL OF MULTIVARIABLE MULTI-STAGE CONTROL SYSTEM

If a control system contains a few digital chains of treatment of information with different periods of quantum, its research is strongly complicated. In the case of rational commensurable periods of quantum transformation of a multirate system it is possible to design an equivalent one-time system with enhanceable
dimension. The general going is offered to the design of an equivalent one-time system, allowing to transform the vectorial-matrix model of the initial multirate system into a vectorial-matrix one-time model of the system, characteristic for vectorial-matrix models of multidimensional continuous systems. Due to that, it becomes possible, in principle, to transfer of methods of analysis of continuous multidimensional systems onto the class of digital-analogue multirate systems.

KNOWLEDGE BASED AND CLP-DRIVEN APPROACH TO MULTI-ROBOT TASK ALLOCATION FOR MULTI-PRODUCT JOB SHOP

Constraint Programming (CP) is an emergent software technology for declarative description and effective solving of large combinatorial problems especially in the area of integrated production planning. In that context, CP can be considered as an appropriate framework for development of decision making software supporting scheduling of multi-robot in a multi-product flow shop. The paper deals with multi-resource problem in which more than one shared renewable resource type may be required by manufacturing operation and the availability of each type is time-windows limited. The problem belongs to a class of NP-complete ones. The aim of the paper is to present a knowledge based and
CLP-driven approach to multi-robot task allocation framework providing a prompt service to a set of routine queries stated both in straight and reverse way. Provided example concentrates on the first case taking into account both an accurate and an uncertain specification of robots operation time

PLANNING AND REALIZATION OF PRODUCTION PROCESS IN A SELECTED TEXTILE ENTERPRISE

This article contains a brief characteristic of a selected textile company. It also presents the description of realization of selected processes directly connected with a production process, starting with foreseeing the rate of sale throughout supply and production planning, and closing with the realization and settlement of the production process in relation to turnover stock. The role of integrated computer systems in the realization of successive stages of the production process is also concerned.

MODELLING AND SIMULATION FOOD PRODUCTS PRO

Modelling and simulation food product production are presented in the paper. There is some information about how to analyse continuous production systems in food industry. As the example we have got here in the paper choosen food product production simulation. There was illustrated optimum production process run. In modelling and simulation there was included food industry specifity. There was take into consideration how components expiration date and production times influence on ready made products expiration date. The problem was solved in support of ARENA module. There is some information about solving problems of machine servicing with taking into account technological changes.

OPTIMIZATION OF TASKS IN AN OPERATIONAL PRODUCTION PLAN IN CONDITIONS OF UNIT AND SMALL BATCH PRODUCTION

In conditions of unit and small batch production a very important role is played by time of product availability for the customer. Despite using modern management techniques setup time still play an important role in the production cycle time. In the examined companies the relation between rearmament times to processing times is still high. The above researches inspired the author to prepare the method of setup times’ reduction through proper arrangement of tasks in the operational production plan. Optimization of the daily production plans is based on two-level division of scheduling and arranging tasks. To counterbalance fluctuations and inaccuracy of operational planning it is necessary to introduce the positive feed-back into the system in a form of registering of operations implementation.

CONTROL BY PARAMETERS OF THE SELECTIVE ASSEMBLING

Models for definition of the amount of incomplete production are offered. The influence of control by parameters of selective assembling on the amount of incomplete production is explored. One-step and multi-step control algorithms are surveyed. Outcomes of modelling are given.

ANALYSIS OF PRODUCTION SYSTEMS ON THE BASIS OF SIMULATION EXPERIMENT

The paper presents results of research obtained on the basis of simulation experiment, whose aim was to analyze the performance of cast iron foundry The computer model of foundry has been planed and conducted in order to compile the schedule of cast production. On the basis of reports from a simulation experiment information was achieved related to activities’ duration, load of accessible resources, the problems of storage and transport, bottle necks in the system and appearing queues in from of workplaces. The research used a universal modelling and simulation packet for production systems - ARENA.

APPLIED A NEW METHOD FOR MULTI-MODE PROJECT SCHEDULING

The aim of this paper is to present a modelling heuristic framework that enables one to cope with a problem of a project-driven manufacturing. The objective is to find computationally effective method aimed at scheduling of a new project subject to constraints imposed by a multi-project environment. The application of a heuristic method of scheduling is demonstrated on one example of a makespan-feasible schedule that follows the constraints imposed by the precedence relation and by the time-constrained resources availability. This heuristic method is based on concept of critical path and branch and bound scheme.