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In the context of production logistics, U-shaped assembly systems often present several advantages compared to straight-line systems. Therefore, such systems are usually evaluated in the planning phase using production logistics and cost-related criteria. However, some published papers illustrate that these advantages may face ergonomic drawbacks. For decision making, the evaluation must be expanded in order to consider these systems from both perspectives. In this way, unfavorable forms of work organization in U-shaped assembly systems can be detected already during the planning phase. In addition, the static methods such as spreadsheet calculations generally used for planning prove to be poorly applicable due to the overly optimistic results they generate, especially in case of model-mix systems. These aspects are especially addressed here and the difference between static and dynamic approaches are illustrated. Consequently, planning solutions must be validated dynamically by means of simulation. Only then can be judged whether the planned production logistics criteria are achievable at all. In addition, the simulation allows for more realistic statements also concerning ergonomic criteria. This approach will be demonstrated here by a near-to-reality planning case. For a comprehensive multi-criteria decision making in the face of production logistics and ergonomics the use of lexicographic ordering is shown.

As a reaction to the volatile market demands with regards to the number and variants of products offered, ever more complex procedures for manufacturing control are being developed. Most recently, self-organising procedures, which often mimic the behaviour of natural systems, have arisen. The method of ant colony optimisation (ACO), which was inspired by ants, can provide the necessary fundamentals in order to realise self-organising manufacturing control. In this context, the ifab-Institute has developed the AntControl tool for self-organising manufacturing control based on ACO. In order to investigate the potential of ACO, several concepts have been developed and integrated into the existing OSim simulation tool to create the new OSim-Ant tool. An exemplary simulation study within a manufacturing system has been carried out to evaluate the behaviour of AntControl. This paper presents this tool as well as the results of the simulation study.

In addition to the traditional consideration of technical and economical issues, staffing aspects are gaining in importance in the planning of production systems. The usual approach is to determine the manufacturing equipment according to the applied technology and then to define the necessary staff. However, this approach may lead to problems after the technical issues have been determined. On the other hand, a reversed approach, namely planning the technical resources based on the personnel to be implemented, is hardly practical. The following article deals with the topic of an integrated, simulation-supported procedure for the planning of personnel and technical resources based on a pre-determined order programme and the corresponding production logistical conditions.

In the majority of manufacturing systems, human resources are the most expensive but also the most flexible factor. Therefore, the optimal utilization of human resources is an important success factor contributing to long-term competitiveness. In order to meet future requirements, which arise from continuous changes to products and technologies, production enterprises are forced to constantly adapt their human resources with respect to the number and abilities of employed persons. In order to accomplish this, it is necessary to define time frames, which allow for at least a rough planning of the needed number and abilities of a workforce. These time frames are determined by the dates when product or technology changes are expected. This already known technology calendar concept has now been enhanced by time frames for personnel development measures. Which worker is suitable for further education and how the respective abilities should be achieved is a subject matter related to the determination of qualitative personnel requirements, whereas the number of needed persons is a quantitative issue. If the required qualifications are to be available at the right point in time, it is indispensable that the necessary qualification measures are defined and scheduled appropriately. The concept, which has been developed here, describes the qualification measures, sorted into target groups, content, qualification costs and time. As a means to meet the personnel requirements arising from continuous changes to products and technologies, the enhanced technology calendar concept will be illustrated by using an application example.

In many manufacturing systems human resources are the most expensive, but also the most flexible factors. Therefore, the optimal utilization of human resources is an important success factor contributing to long-term competitiveness. With regard to the qualification of the workforce, there exist a large number of possibilities for varying the abilities of employed persons and for allocating them to tasks. Of course, the chosen assignment has an important effect upon labour cost and on the achievement of typical logistical goals. In order to consider the plurality of possibilities for personnel assignment and to exploit the flexibility of human resources, effective planning tools are needed. For this purpose, the ifab-Institute of Human and Industrial Engineering at the University of Karlsruhe exploits the possibility of using simulation as a planning tool, e.g. for re-assigning personnel to tasks in the middle term. Dependent upon the type of personnel assignment problem various tools have been developed, e.g. the personnel-oriented simulation tool ESPE (Engpassorientierte Simulation von Personalstrukturen). This article will explain, using one case study with varying questions, the procedures and the solutions for different types of personnel re-assignment problems.

Analogous to the well-known concept of product prototyping during the design phase of a new product, this paper discusses an approach for the prototyping of organisational structures of production systems. The procedure uses simulation techniques and is based on a special characterisation of the order processing. Specific process attributes are consulted for applying elementary structuring strategies, such as customer, order, product, task or process orientation. The procedure will be demonstrated through a case study of a company in the mechanical engineering area. With its help, a suitable departmental structure can be defined in order to integrate a new order type into the existing structure while increasing the performance of the entire production system.

During the realization of the CAESAR planning games, which has been supported by the European Leonardo da Vinci Programme, the use of modular planning games within a global scenario has shown to be very effective in concisely relaying educational content from the area of production management. In particular the close-to-reality situations have proven, time and again, to be highly motivating for seminar participants. In order to improve the transferability of acquired knowledge into practise, the ifab-Institute of Human and Industrial Engineering of the University of Karlsruhe has further developed the INSIGHTS-PPC planning game for production planning and control, in such a way that the planning tasks to be tackled are set in direct relation to market similar repercussions. This is realized in a new market share model. The market share model will be explained, paying particular attention to the practical consequences which come along with the implementation of such a model. Despite the potential of the de...

The simulation of production systems usually requires rather detailed data, concerning the duration of the modelled activities, which determine the quality and reliability of simulation results. Application in industry has shown that these data are usually available for manufacturing. However, for non-manufacturing tasks, only rough data are available as expert guesses. Therefore, in order to simulate complex production systems which include manufacturing functions as well as pre- and post-manufacturing functions, it is often necessary to combine simulation models with different levels of detail. Therefore, an adequate approach is needed in order to avoid inconsistencies in results. Such inconsistencies may be connected with different levels of detail and occur if i.e. a highly detailed manufacturing model is combined with a more global simulation model for the winding-up of customer orders. The solution until now has been to define a simulation model with only one unique level of detail. If highly specific results are needed, the user is forced to build a very detailed model of the whole production system. Often, this turns out to be either impossible or connected with too much effort. If more global models are used instead, the obtained results may be insufficient to render an answer to the user's questions. At the ifab-Institute of the University of Karlsruhe, a new simulation tool OSim, which allows for the integration of variously detailed submodels into an overall global model of the investigated production system, is under development. The consistency of different models is guaranteed by a specific method of coupling the models. In this hierarchical way, the global simulation model can be combined with various submodels which contain more detailed processes. These detailed processes are then synchronised with the processes of the global model. For this purpose, the global model initiates an underlying process which then delivers its result to the global process. This combination of variously detailed models can be extended hierarchically. Following the description of this new simulation concept, a practical example for application will be given. This example is derived from an aluminium factory. It concerns the simulation of the overall winding-up of customer orders with their underlying manufacturing processes. The consistency of this simulation approach will be demonstrated by evaluating logistical key data at various levels of detail.

In the realm of enterprise reorganization, terms such as process orientation, group work, segmentation, and de-layering of hierarchical structures are frequently discussed. Growing needs of support, before and during enterprise reorganization, calls for methods to assist the change process to the highest possible degree. During recent years, several methodologies and tools for modelling and designing enterprises were developed. This paper describes an approach using the GRAI-methodology for modelling the functional, physical, and decisional structure of production systems, respectively. Upon completion, the created enterprise models are transferred into the simulation system FEMOS for dynamical analysis. After describing the theoretical background, the paper demonstrates the effects of decisional adaptations using two case studies completed during the ESPRIT project REALMS (re-engineering application integrating modeling and simulation). The first case looks into the impact of decreasing the number of hierarchical layers with respect to a one-of-a-kind production system. The second case shows the effects of re-engineering a function-oriented production system with several department interfaces to a process-oriented organization.

This paper discusses a simulation aided approach of economy and productivity measures for organizational changes based on activity costs. The procedure is supported by the simulation package FEMOS in order to evaluate the planned production system dynamically. During the simulation run the activities will be executed exploiting the resource capacities of the system. The activity costs are calculated based on a resource cost model. This model consists of static cost factors for the resources which will be adapted during simulation in order to take into account the actual or planned production situation. With the help of an example it can be shown, that the calculation of activity costs is useful in reengineering processes.

Requirements upon modern production systems have changed considerably. One of the main results of these changes is that organizational improvements have become more and more important. In contradiction to this, the available approaches to support adjusted design of production systems in an early planning stage — especially regarding manual assembly systems — are deficit. Particularly, the consideration of process organizational effects by determination of the job division fails because the planning knowledge is limited to rather vague hints than based on precise planning rules. An analytical approach for the determination of job division in assembly systems under different goals has been developed to overcome this weakness. Basis is a parametric description of the important factors of the planning problem. Set up on this, a simulation-based investigation has been carried out to detect dependencies between the goal system and the assembly tasks. The result is an analytical approach based on regression models to determine a suitable form of job division for a clear-cut assembly task.

Having been forced by the development of international markets, producing enterprises are presently searching for possibilities to improve their order processing. Besides technical means, new organizational concepts which can be characterized by a process orientation are under consideration. Examples for such concepts which consider the entire order processing from order entry to delivery are order centers, production segments or the concepts of lean production. In connection with the realization of new forms of organizational structures, an enterprise has to decide which form of structure tends to produce the best system behavior in given circumstances. Up to now, general statements concerning the suitability of different forms of structure have not been available. Therefore, specially adapted solutions must be developed according to the given production conditions. As the evaluation of their suitability requires the examination of the dynamical system behavior, a simulation tool has to be used in order to completely evaluate the effects of the different possible solutions. A simulation-aided approach will be presented for the design of the organizational structure of production systems by using a case study as an example. In a mechanical engineering enterprise which produces conveying systems the production situation can be characterized by a strong customer-orientation. Each order refers to a special conveying system consisting of different components which are arranged individually. With the help of the simulation tool FEMOS, a suitable structure for the winding-up of orders in the pre-productive functions will be developed. This case study results in a proposal for the reorganization of the departments for design and operations planning.

This paper deals with the problems of staff planning, especially in highly automated production systems. In planning such systems, it is not sufficient to reflect only on technical details, but it is necessary to consider modern forms of work organization as well. As a planning tool to quantify dynamic processes, simulation will be used. After discussing the need for personnel-oriented simulation tools, two simulation studies will be presented, both focusing on planning the work organization in highly automated production systems in the field of mechanical engineering. The paper concludes with an outlook on future efforts in the regarded field of research.

Changes in international competition lead to changes of the requirements on production enterprises. The introduction of new production technologies does not seem to be exclusively an adequate reaction to the increasing problems. Therefore tools of computer-integrated production lCIMr and new organizational concepts have to be conceived. Because these organizational and technical means are linked on the one hand with severe changes in the production system and, on the other hand, with rather higher economic risks in their realization, the effects have to be estimated in advance in the planning stage. Consideration of dynamical system behaviour plays an important part because the main goal is the improvement of order processing. This paper presents a simulation program, which can be used during the design phase of the organizational structure of production systems as a powerful tool for predicting the effects of new computer-aided tools and structures.

In order to meet technological and economical demands, industrial enterprises have to reconsider their organizational structures. Especially on the shop floor level, new types of work structures are required to increase flexibility and productivity. However, the effects of such changes on certain indicators (e.g. dynamic capacity of production lines, lead time of jobs) can hardly be calculated during the planning processes. For this reason the use of simulation programs is often recommended. In this paper a simulation program is presented which allows us to investigate the effects of various numbers and qualifications of personnel employed in a specific work shop. For this purpose, the program incorporates three different types of input data concerning the production program, the equipment and the qualification of personnel. Due to this, results can be achieved on the loading of the personnel as well as the machines and the dynamic capacity of the production system. The economical results can be evaluated in terms of cost. The practical use of this simulation program is shown by an example concerning a special planning case.

Bei praktischen Personaleinsatzproblemen erweist es sich oftmals als nicht sinnvoll, die Entscheidung auf der Basis nur eines Kriteriums zu treffen. Falls mehrere, nach ihrer Prioritat geordnete Kriterien die Wahl eines Zuordnungsplans bestimmen, ist ein lexikographischer Ansatz geeigneter.