Simulation

This paper presents a simulation study that has been carried out at the Container Terminal Altenwerder in Hamburg in order to examine various topics related to the dispatching of automated guided vehicles (AGVs). After on overview of the structure of the simulation model, the application to the project is discussed. Several simulation experiments are summarized in order to demonstrate the broad applicability of the model.

Shorter product lifecycles, customer-oriented production and raising variants of the manufactured goods are representative for today’s industries. One well-established method for planning, safeguarding and improvement of production processes is the material flow simulation. In order to cover all phases of the process development, a backward-simulation approach beside the usual method is needed. The generated simulation results are moreover to be integrated in “control centre”-views, wherefore a time-oriented execution of the simulation has to be added. This article shows some functions of the material flow simulator d³FACT insight, which already allows to execute simulation models in forward or backward direction, as well as a time-oriented simulation.

Advanced Planning or Supply Chain Planning constitutes a sub-task of Supply Chain Management. It focuses on planning of operational processes, and hence has its primary area of application in manufacturing and distribution of physical products. Advanced Planning Systems (APS) build upon databases of ERP systems. They enhance the latter by a concept of hierarchical planning which makes use of modern methods as developed in Operations Research and related fields. This article gives an overview of solution methods implemented in APS and modelling capabilities.

In order to achieve a flexible reaction to fluctuations in demand the operative working times have to be rearranged. Often flexible working time models are implemented, whose configurations are problematic from personnel and operative points of view. In addition, the currently available evaluation methods turn out to be highly subjective. This article will present a simulation-based working time configuration which allows for a prospective evaluation of working time models.

The paper describes a game called the Supply Net Game, built around the structure of a production supply network based on the “anchoring and adjustment heuristic” which is known as the one people use to make inferences about uncertain events. The game involves four players where everyone manages his manufacturing unit that consists of four production lines which proceed to the joint development of products with the other units. While planning production and controlling inventories, every person should try to minimize the costs caused by both holding items on stock and being in an out-of stock situation. The paper stresses the valuable impact of management games for production engineering education in general and particularly the significance of learning implicit skills as well as gaining insight in inventory control and management of complex distributed production systems such as the system dynamics production network model introduced in the paper.

Modern supply chains today consist of a wide network of production and distribution sites, suppliers, vendors and customers. Moreover, the complexity of such sytems is affected by great dynamics and a multitude of degrees of freedom. The rising number of variants, short delivery periods and the severe competition for instance call for a high degree of flexibility to adapt to the permanently changing market needs. Stability - and with it an increase of productivity and cost reduction - can only be achieved when all activities within the supply chain are based on a holistic and end-to-end planning scenario. In the ideal case it should map each link of the supply chain.

This technical contribution presents a digital planning environment for an integrated facility layout and logistics planning. The aim is a noticeable reduction of time and effort for middle- and long-term facility planning and production planning. Therefore current data from the shop floor and order management are provided in an object-oriented consistent digital structure. This data is used to forecast the need for action and to deduct alternative solutions. Planning becomes more effective, long-term planning tasks become day-to-day activities so that the flexibility of the enterprise increases.

Although the relocation trend has slightly decreased during the last five years, nowadays more companies plan to shift abroad in the near future. In particular small- and medium-sized companies plan the relocation of parts of their value chain. The disadvantage of the German location can only be compensated by a combination of cost optimization and an increase of productivity. A systematic procedure and the application of sophisticated evaluation tools support the company in its process of decision making. Considering the type of business, guidelines for competitive value chain management can be developed.

Technology driven industries are facing new challenges to manage the spare part business of high-quality products due to decreasing innovation cycles and increasing product complexity. An influencing factor for the total profitability is the after-sales strategy for spare parts after the end-of-production decision of a product. On the one hand the guaranteed service level can be achieved by excess stocks and expensive scrapping actions. On the other hand if out of stock situations may occur, penalties and an eventual image loss have to be taken into account. Both strategies can be combined to reduce costs significantly by using a dynamic life cycle simulation approach.

High dynamics and structural complexity in current and future logistic systems are complicating central planning and control. For enabling a more decentralised and autonomous control, communication between the elements of the logistical network are necessary for the provisioning of the information needed. This article details the modelling of the communication between the components. This modelling contains source and sink of the information as well as the amount of data, frequency of transmission, quality of service and the moment of transmission for a reasonable usage of the information. The technical feasibility with current and upcoming communication systems is evaluated under consideration of the model.