MODELLING OF AUTONOMOUSLY CONTROLLED LOGISTIC PROCESSES IN PRODUCTION SYSTEMS

Abstract: The increasing complexity in order processing of today’s logistics systems requires a reorganisation of existing planning and control systems, which do not allow a fast and flexible adaptation to changing environmental influences. Autonomously controlled logistics proc-esses seem to be an appropriate approach to meet these new demands. In the context of this paper the changes in modelling of autonomously controlled logistics processes are investigated. At first a definition of autonomous control in general and within the scope of engineering science is introduced and its main criteria are described. Based on this changes in order processing by establishing autonomous control are investigated and exemplarily illustrated in several views of a business process model. Keywords: Autonomous Control, Modelling, Logistic Processes 1. INTRODUCTION Rapidly changing conditions of present markets lead to an increasing complexity of logistic systems and require innovative approaches to organisation and control of logistic systems. Typical examples of market-driven changes are the increasing importance of customer orientation because of the shift from seller to buyer markets, shorter product life cycles and decreasing lot sizes with a simultaneously rising number of product variants as well as higher product complexity [13]. As a result new demands were placed on competitive companies, which require innovative logistic concepts and planning and control methods to ensure a high flexibility and adaptability of the logistics system to changing environmental influences [8]. Conventional production systems are characterised by central planning and control methods, which show a wide range of weaknesses and cannot fulfil these demands. Conventional planning and control methods are based on simplified premises (predictable throughput times, fix processing times of production orders etc.), which lead to an inadequate and unrealistic description of the production system. The different centralised planning steps of the traditional ERP respectively MRP based PPC-Systems are run sequentially, therefore the adaptation to changing boundary conditions (e.g. planning data) is only possible within long time intervals. This means that changes of the job shop situation cannot be considered immediately, but the next planning run at the earliest. As a result the current planning is based on old data and the needed adaptation measures cannot be performed in time for a proper reaction of the discrepancy between the planned and the current situation [14]. In case of disturbances or fluctuating demand centralised planning and control methods are insufficient to