Dynamics

Job-shop-productions are facing high requirements due to the high diversity of manufactured products, changing lot-sizes and strongly cross-linked material flows. This situation is intensified by dynamic effects which are caused by non-linear dependences between the system’s parameters. The complex dynamics can affect the logistic performance of the system by varying stock-levels, rising cycle times or decreasing capacity utilisation. This paper describes an approach to analyse the effects of the factory planning process on the system’s dynamics, whereat the focus will be on the planning subtasks of dimensioning and structuring. This is expected to improve methods of design for job-shop-productions.

Planning and control of logistics processes is more and more determined by an increasing complexity of structure of logistics networks and dynamics. However, in many aspects methods and tools for a comprehensive analysis of large-scale logistics networks are missing. This set of problems is the object of investigation in the new research project ‘Stability, Robustness and Approximation of Dynamic Large-Scale Networks - Theory and Applications in Logistics Networks’ founded by Volkswagen Foundation. The project will be run in a dual way: Mathematicians from the university of Bremen und the university of Würzburg cooperate with researchers from the field of engineering of the university of Bremen.

European companies which are producing on customers demand, have to face a highly turbulent competitive environment. The main challenges are short production cycles, high customer requirements, globalisation as well as competitors from developing countries. A solution to the resulting high dynamic and complexity are cooperative management approaches like supply chain management and the set up of specific flexibility potentials.

Producing companies are increasingly facing external dynamics. To remain successful in the long run their management will have to keep up to this challenge. Thus it is important to choose and implement the right concepts and instruments to deal with dynamics. This article offers an overview on different approaches and a closer insight into the concept of Supply Chain Event Management.

Very often material flows within or between companies seem to behave in an irregular manner, which can cause inventory levels to become unpredictable and poorly manageable. This behaviour can especially be observed at high utilisation ratios of means of production or logistics. Commonly, it is assumed to be caused by small disturbances, which can never be completely excluded in practice. For that reason often large efforts are made to minimise disturbances, but the question arises, if it always has to be disturbances that make predictions of e.g. inventory levels difficult for the near future and practically impossible in the long run. Using a small, but re-entrant manufacturing system, this article presents in-vestigations on how even relatively simple networks can develop irregular dynamics.

Suppliers in turbulent markets find themselves confronted with additional logistical challenges. Customer orders and market demand may be satisfied through the development of a high reaction potential within the company. In order to adjust the production accord-ingly and to demonstrate the logistical abilities to the customers, logistical agility has to be measured and assessed first. A possible approach is the mathematical description of the synchronisation of production and distribution based on throughput diagrams.