Search

Due to the increasing competition in global markets, many European garment manufacturers have had to undergo significant restructuring and were forced to create leaner value-adding processes. As a result, the majority of the manufacturing operations have been outsourced to low labor cost countries. At the same time, production logistics as well as information and communication technologies have gained importance, in order to keep job functions requiring higher qualifications within Europe. Another challenge concerns the introduction of customized products into the production processes which previously had been designed for manufacturing of large volumes. Prior to implementing such changes, the consequences with respect to production logistics as well as the financial impacts should be examined. The case study presented in this paper uses a simulation tool for these purposes. Different scenarios developed for a garment company were analyzed. Based on the results, recommendations for the further development of the regarded company were deduced.

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.

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.

This paper presents research activities associated with the development of a simulation tool for modelling human reliability in production systems. This dynamic model enables the planner to determine the consequences of changes in human reliability on the quality of the production processes and the products. The model is built upon the basis of a tool for human reliability analysis ESAT (Experten-System zur Aufgaben-Taxonomie; Aufgabentaxonomie: Ein Verfahren zur Ermittlung der menschlichen Leistung bei der Durchfuhrung von Aufgaben, Messerschmitt-Bolkow-Blohm, Ottobrunn, 1990.) and a personnel-oriented simulation programme ESPE (Engpassorientierte Simulation von Personalstrukturen; Ein engpassorientierter Ansatz zur simulationsunterstutzten Planung von Personalstrukturen, Dissertation, Karlsruhe University, 1994), developed at the ifab-Institute of Human and Industrial Engineering at the University of Karlsruhe. In addition to the definition and the calculation of the human error probabilities, the consequences of the human errors (i.e. rework and waste) for the quality of the processes and the products were also implemented. This method is able to systematically plan quality-oriented assignments of personnel to functions and workplaces (personnel structures) in production systems. The effectiveness of the method is demonstrated by a case study.

The short-lived nature of products requires production enterprises to plan new production systems in ever shorter intervals. The enterprises are thus prompted to improv their planning processes and in particular to shorten their planning times. Computer supported planning tools can be used to develop planning alternatives and to examine them, using simulation, with respect to their dynamic attributes. A substantial problem can be seen in the conception of a hybrid assembly system containing a similar amount of automated and manual stations. The procedure PAMELA was developed at the ifab-Institute of Human and Industhal Engineering at the University of Karlsruhe for the design of suitable planning solutions for hybrid assembly systems (Muller 2002; Zulch. Muller 200la).This procedure is based on the description of work content and the dependencies of assembly operations as well as several layered precedence diagrams. Simulation is called upon for the assessment and choice of alternative planning solutions. The use of the procedure PAMELA will be demonstrated in this article using an application example.

During a project in the frame of the European Leonardo-da-Vinci-Programme five simulation games have been developed in order to engage awareness of the participants for problems in real production processes. The games focus on different areas of the production environment and are based on a common scenario: the optimisation and redesign of a bicycle production. The simulation games have been played by both industrial managers and students and could succeed in team oriented education. Additionally, the completion of a book describing the games and including software versions of the used simulation tools enables self-training in the field of production management. In this paper the common scenario of the simulation games will be presented. Two selected simulation games will be arranged according to a game classification scheme in order to characterize the games. The advantages and disadvantages of the two different kinds of learning methods — self-training and team oriented education — are also shown with the help of the classification scheme.

This paper discusses a process-oriented approach for designing organizational structures of production systems. Based on a suitable characterization of order related processes on one hand, and the personnel on the other hand, organizational structures with a high performance can be defined. The concept of shaping process-oriented organizational structures is connected to a simulation-aided approach in order to evaluate the dynamic behavior of planned production systems and to perform the planning procedure in a flexible and efficient way. The dynamic analyses are carried out using the simulation tool FEMOS.

The integrated simulation game for planning and reorganizing production systems has been developed at the ifab-institute in order to engage the awareness of the players for actual problems in real production systems. During the planning game the participants have to act on operative level as well as on strategic issues. First they have to plan and control the production of an existing assembly system for producing bicycles in planning teams. The system is modeled using the simulation tool FEMOS. Running the factory the teams are going to detect weak points inside the existing system. This experience is the basis for reorganizing the assembly system afterwards. The paper consists of demonstrating the principle structure of the planning game, the material used as well as an illustration of different planning results obtained by playing the game with students and professionals.

Market dynamics call for a high degree of adaptability on the side of the companies. Reacting quickly and in a flexible way to changes of customers requirements is a decisive performance indicator. With these changes it becomes more and more important to employ cost intensive personnel resources in the most effective way. Even in the case of a newly developed production system the determination of the future personnel structure is a complex planning problem. Re-organization of personnel structures needs to consider all vocational restrictions and personal preferences of the employed persons. In order to solve this complex planning problem, an approach for systematic re-organization of personnel structures was developed. This method is able to adapt personnel structures to the continuously changing general conditions by observing economical and logistical goal achievements.

Due to increasing international competition, productive enterprises are currently searching for measures to improve their order processing. As the major potentialities for further improvements are strongly connected to the organization of production systems, the organizational performance has to be investigated and evaluated.