Prof. Dr.-Ing. habil. Peter Nyhuis

Managing partner
+49 (0)511 279 76-119


The volatility of electricity prices is steadily increasing due to the growing expansion of renewable energies. This is particularly observable at the electricity exchange. Small and medium-sized enterprises (SMEs) in the manufacturing sector can save energy costs due to these fluctuations through targeted load management methods. To increase this potential, SMEs need to use smart meters and obtain their electricity at pricest as close to those at the electricity exchange as possible.

power procurement, electricity exchange, load management, electricity costs

The forecast of sales volumes represents a challenge for the production planning. Above all, sales forecasts that are difficult to predict, such as those caused by promotions, are obstructive. Often, additional information from macroeconomic indexes is not topical, the level of detail of products to be forecast too low and the forecast expenditure too high. Aim of a research project therefore is to develop a model based on search engine data to forecast sales volumes at product level. By the use of complementary application of search engine data to the sales forecast is expected that the forecast mistake can be reduced compared with conventional forecast models upon product level. In general it should be clarified whether and in which extend the logistical efficiency of an enterprise can be improved by search engine data based forecast of sales volumes in the production planning.

production planning, sales forecast, search engine data, forecast model

In production, product-based failure costs can be reduced by focusing the production factor „human“. Therefore, human performance fluctuations during the course of day have to be considered in the production planning and control. This paper presents an approach for quality-orientated flexible job shop scheduling, taking into account human performance fluctuations during the day.

production planning and control, performance curve, quality

Assembling large-scale products involves frequent process interruptions why in order to reduce the impact of interruptions, a short-term response is necessary to reduce delivery delays and idle times of resources. An approach to challenge this represents the flexibility of a production system. Regarding the environment of large-scale product assembly, it has to be shown which potentials of flexibility are able to be used in a short-term manner.

assembly, production management, disruption management

Considering production planning and control, lot sizing is a very important task. Lot sizes are usually resorted to lot size dependent order and storage costs. However, models for lot sizes ignore the aspect of lot size dependent maintenance costs. For forging companies the tool wear has a great economic importance, because the tooling costs represents a major factor in production costs.

production planning and control, lot sizing, process stability

Rising electricity prices for industrial companies result in increasing energy costs and thus lower international competitiveness. Due to increasing electricity price fluctuations, savings in energy costs without capital-intensive investments are possible by implementing specific organizational methods to process energy-intensive orders at times of low prices and energy-low orders at times of high prices.

energy costs, energy price, manufacturing control, sequencing

Disassembling of large-scale products (e. g. wind energy plants, crane and conveyor systems which are known as XXL-Products) becomes increasingly important, as the operating time is limited. The challenge is to optimize the positioning of the complex and expensive disassembling on the operation site on the one hand and the costly transportation of modules to the disassembling factories. For this reason the location and allocation problem will be pictured in a mathematical model within the research project “DemoNet”. This model supports companies to create a XXL-disassembly-network. The research hypothesis assumes: a disassembly under ecological, economical and logistical aspects constitutes the optimum. The extension of a location planning tool forms the basis of the mathematical optimization model for the disassembly of XXL-Products. For solving the problem a genetic algorithms will be used. The result helps companies to arrange disassembling networks for XXL-Products efficiently.

dismantling planing, dismantling networks, impact model

Controlling the time synchronicity of supply processes for assembly requires a quantitative measure. An existing controlling instrument, the supply diagram, already provides an effective way of assessing the supply situation. It incorporates different key figures which allow for an evaluation of a company’s supply process coordination. However, it lacks a key figure for describing the level of time synchronicity. Therefore, a quantitative evaluation of actions to improve the time synchronicity in supply processes is not possible. Based on an existing approach of approximating the completion of full assembly orders, a key figure for describing the level of time synchronicity is developed in this article: the synchronicity factor. As this new key figure is dependent on the average number of components required for one assembly order for the regarded time period, a second measure, the relative synchronicity factor, accounts for this number and can thereby be used to compare different time periods. As the numerical calculation of the synchronicity factors is a complex problem, the possibility of applying a simple hill climbing algorithm to accurately determine the synchronicity factor for a certain supply situation is examined.

Production planning and control, supply chain management, supply diagram, time synchronicity

The ongoing change from make-to-stock to make-to-order production and the increasing interaction in value creation networks lead to growing challenges for companies regarding delivery date and delivery quantity flexibility. This leads to increased work load scatter in the production systems of companies. This paper presents a simulation-based approach on how the work load scatter can be reduced to a lower level and how this influences logistical characteristic lines.

load scattering, load variation, quantification, batch splitting

Production companies are faced with an increasingly turbulent business environment, which demands very high production volumes and delivery date flexibility. If a decoupling by storage stages is not possible or undesirable from a logistical point of view, load scattering effects the production processes. This expresses itself in the form of heavy load scattering. What kinds of quantification of the load scattering exist and how these have been further developed is subject of the following article.

load scattering, load variation, quantification, production planning and control

Increasingly rising electricity prices endanger the competitiveness of the German industry. If fluctuating electricity prices resulting from renewable energy are used, a reduction of production-related energy costs is possible. Therefore the capacity control opens a new field of action. In this paper, a backlog control is introduced, which selects the time of adjusting the capacity in response to energy prices.

time variable electricity prices, fluctuating energy consumptions, manufacturing control, capacity c

Compliance with punctual delivery under the high pressure of costs can be implemented in the forge industry through the optimization of the in-house tool supply. Within the Transfer Project 13 of the Special Research Department 489, a mathematical model was developed which determines the minimum inventory of forging tools required for the production, considering the tool appropriation delay.

production planning and -steering, production management, tool inventory reduction, servicelevel, fo

Increasing electricity price fluctuations through the augmented integration of renewable energies require dynamic tariff plans in order to conform the energy demand on the energy offer for achieving network stability. If time-variable electricity tariffs taking account into the specific needs of small and medium enterprises (SME) can be developed, energy costs can be reduced significantly by freedom degrees of an adapted manufacturing control.

energy costs, electricity tariff, manufacturing control, renewable energy

Forging companies are often suppliers of the automotive industry, which has, by the implemented principles of Just-In-Time production, particularly high demands on the logistics performance of their suppliers. Moreover, the cost pressure in this industry is very high, so forging companies are striving to minimize their logistics costs. One of the factors influencing these logistics costs is the amount tools in a company’s tool inventory. Since the tooling costs have a high percentage of the product costs, strategic positioning between logistics performance and costs in the forging industry holds great potential. However, while a too low number of tools may cause delays in production and more frequent setting-ups caused by division of production lots and a concomitant increase of setting-up times of up to 30%, a possible consequence of too high tool inventories is the increase of process uncertainty by a prolonged and more stray tool circuit pass-through time. A structured approach to the positioning of the tool supply between logistics performance and costs is presented.

production planning and -steering, production management, tool inventory reduction, servicelevel, fo

There is a high potential for optimization in positioning a forging company’s tool supply between logistic costs and performance. Based on a model, which was developed for the improvement of the internal tool supply in the transfer project T13 of the CRC 489, a controlling instrument has been deduced to relate the weighted service level and the stock of the tool supply cycle.

production planning and -steering, production management, tool inventory reduction, servicelevel, fo

Rising costs for electricity endanger the competitiveness of the German industry. If the volatility of electricity prices and fluctuating energy consumptions are used purposefully by the manufacturing control, a reduction of energy costs without capital-intensive investments is possible. In this context the following article describes the development of a sequencing method considering work order-specific energy costs.

time variable electricity prices, fluctuating energy consumptions, manufacturing control, sequencing

While definitions already exist for smaller scale device structures e. g. nanotechnology, the conceptual distinction between standard large products and large scale or XXL products is currently insufficient. This study presents a basic definition of large scale products. At first hypotheses are being derived and examined at an empirical study of three sample products threaded nuts, screw presses and passenger aircrafts. It will be shown that the transition from conventional products to XXL large scale products is characterized by a disproportionate increase in the ratio of product costs to the augmentation of a characteristic product’s feature. Based on the results a definition for the characterization of large scale products is established referring to the technical, organizational and economical restraints and to the available processes and tools.

xxl-product, large-scale, xxl, definition

The range of structure sizes for industrial products produced today is increasingly expanding. This trend is evident in both small-scale (e.g. semiconductor applications) and large-scale (e.g. wind turbine rotors) products. While definitions already exist for smaller scale device structures, the conceptual distinction between conventional large products and large scale products is currently insufficient. In this study, we present a potential basis for the definition of large scale products. To achieve this, we derive hypotheses and examine these in the context of an empirical study using the examples of several sample products. It is shown that the transition from conventional products to large scale products is characterized by a disproportionate increase in product costs due to the augmentation of a characteristic product feature. Eventually we derive a proposed definition which characterizes large scale products in the field of production engineering.

xxl-product, large-scale, xxl, definition

Increasingly demanding markets and reduced production depths force manufacturers of complex products to better coordinate supply processes for assembly. In this article a research project is presented which aims to develop a control procedure for companies to react on delivery date deviations in supply processes. Particularly, as companies act as part of a network, a reasonable behavior in that perspective is sought.

company networks, simulation, supply processes, supply chain management, cooperation

The industrial production process is subjected to a high coordination and communication needs arising from the division of labor as a result of specialization. Trade-offs are omnipresent. For decision making the used indicators often do not have the same information base. The information-based reorganization of tasks can help here. The aim is to increase the decision quality and speed.

task allocation, information needs, organizational design, production indicators