As a result of the energy turnaround and the expansion of the grid, energy-intensive manufacturing companies are confronted with further increases in energy costs and are urged to reduce them through their own measures. In this context, energy costs can be positively influenced by organisational measures, whereby the actual power requirement remains unchanged. This can be done within the machine allocation planning.
However, logistical target values, such as a high delivery reliability, must not be neglected. Therefore, in this thesis a method for energy- and logistics cost oriented machine allocation planning was developed, which considers energetic and logistic target values simultaneously during planning. In the developed method, the planned peak load was used as an energetic target value and valued monetarily via the performance price. The planned schedule deviation in order issue was used as the logistical target value as the target value in the method and was valuated in monetary terms via the stock of manufacturing orders with early planned completion.
The developed method was converted into a mathematical model and a problem-specific algorithm was developed to solve the model. By applying the developed method it could be confirmed that with the additional consideration of the energetic target figure planned load peak in the machine allocation planning, the total costs resulting from the implementation of the planning can be significantly reduced compared to a sole consideration of the logistic target figure. Furthermore, the qualitative effects of the variation of the considered input variables on the total costs resulting from the implementation of the machine allocation plan could be shown.
Machine occupancy planning, energy costs, performance price, schedule deviation
The digital development of spaces within the city of Hannover by means of a digital image makes it possible to cover the usage needs of spaces more efficiently and in line with the requirements. The crea-tion of a digital image, which develops new possibilities for access to public space, requires the use of different sensors such as LiDAR sensors and tracking cameras. In order to select suitable sensors that can be used with UAS, the requirements for the overall system are first defined, which are derived in functional requirements for the sensor technology. Subsequently, the degree of fulfilment of the functional requirements by the different sensors
5G, UAS, digital image, digital twin
In this paper, objective functions for the optimisation of modular conveyor systems will be introduced. Modular conveyor systems consist of conventional as well as modular conveyor hardware, which are arranged in form of matrix-like layouts. The aim of an ongoing research project is to provide small and medium-sized enterprises with a user-friendly decision support for the selection and planning of modular conveyor systems. For this purpose, the conveyor systems should be evaluated according to the objectives throughput and space requirement. Therefore, mathematical equations have been developed, which enable a fast and precise evaluation of layouts. The paper focuses mainly on the efficient calculation of the throughput. The result quality of the evaluation equations regarding the throughput was proven by a simulation of example systems.
modular conveyor, conveyor system evaluation, throughput analysis, layout optimisation, logistics
For more than half of the approximately 30,000 wind turbines in Germany, the 20-year EEG funding will end in the next ten years. It is still unclear what the optimal technical and economic strategies for end-oflife utilization might look like. The BMWK joint project „TransWind“ aims to analyze the end-of-life issue on a micro- and macro-level in a transdisciplinary manner to support stakeholders from politics, the wind industry, and the resource and recycling sector in the selection of end-of-life strategies.
wind turbines, end-of-life, ecology, dismantling, repowering, disassembly, recycling, XXL products
How can companies get the most out of their manufacturing and be economically successful even in a high-wage location? A Manufacturing Execution System – a process-oriented level of a multi-layer production management system – can help. This enables companies to optimize their production planning and control.
A large number of small and medium-sized enterprises (SMEs) currently still do without this support because the effort required to introduce such a system appears too great. One way to reduce the effort involved is to prepare comprehensively for the MES introduction. An "MES Readiness Check" should provide support for this preparation. It reveals the demands that this introduction phase places on companies. The company can check whether it meets the necessary requirements.
Manufacturing Execution System, MES, Digitalization
During the assembly of large-scale products, disruptions often occur. To reduce these disruptions, a straightforward approach to their systematic processing is needed. This should automatically identify similar disruptions and independently suggest sensible corrective measures. For this, the disruptions are first collected and characterized and a model for practical information flows is created. Then, in a multi-stage similarity search, similar disruptions are identified, and suitable corrective measures are derived.
Disruption management, single and small batch assembly, large scale products, similarity search
In this paper, a new solution for the facility layout problem is presented. The approach was integrated into a planning software. The aim of the MeFaP research project was mainly the development of a user-friendly decision support regarding the facility layout problem for small and medium-sized companies. Therefore, a realistic modelling of the planning problem was focused on. Thus, a path planning with area allocation was integrated, for example. The metaheuristic Tabu Search was selected as a solution approach. To ensure an efficient optimisation, the optimisation is performed in two steps, once without and then with route planning. The experiments were performed with the objectives material flow distance, temperature and cleanliness, which are briefly described. The results of the experiments were compared with current solution approaches.
facility layout problem, factory planning, multi-criteria, metaheuristic, tabu search, software
Maturity-based Evaluation of Requirements for a Successful MES Implementation. The use of a Manufacturing Execution System (MES) can offer many advantages for companies, but the implementation often poses a great challenge. The determination of necessary requirements, their fulfilment by the company and their consideration in the implementation process are decisive for a successful implementation. In the following article, the development of a maturity-based method for the evaluation and improvement of the companyspecific fulfilment of the requirements of an MES implementation is presented.
Manufacturing Execution System, Maturity Model, Digitalization
In production, product-related error costs can be reduced by focusing on human production factors, such as considering human performance fluctuations during the day, when production planning with respect to job-shop scheduling. In this article, the flexible job-shop scheduling problem is extended by considering product-related error costs and logistic costs. Product-related error costs are increased by over stressing the operative workers. Logistic costs are based on work in process and throughput time. This cost-based definition enables a production plan to be simultaneously optimized in respect of both error and logistic costs. The product-related error costs and flexible job-shop scheduling problem are described mathematically and a memetic algorithm is also presented as an approach. Within the memetic algorithm, the evolutionary process is supplemented with a local search procedure to improve the ability of solutions and repair procedures to rectify infeasible solutions. The influence of product-related error costs on the total costs of a production plan within job-shop scheduling is presented.
flexible job shop scheduling, memetic algorithm, human perfor-mance fluctuation, error costs
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
Assembling large-scale products involves frequent process interruptions. To reduce the duration of an assembly stop, the WZL of RWTH Aachen University and the IPH Hannover developed an approach which is able to identify alternative assembly plans and to evaluate them on the basis of the logistic performance objectives. Stock, capacity utilization, lead time and adherence to schedule are transferred into costs and assembly plans are thus comparable based on one parameter.
production planning and control, assembly, logistical objectives
The use of 3D printing techniques gives manufacturing companies the opportunity to implement new production processes and to unlock economic potentials. In this article a research project is presented, which aims to analyse the use of build-operate-transfer models with 3D printers. Thereto an evaluation and implementation tool for build-operate-transfer models is being designed, which considers the perceptions of the suppliers and the costumers.
3D printer, build-operate-transfer models, production organization, profitability, production logist
When designing logistics processes, the demand for an environmental sustainability is increasing. Often companies have a choice between different alternatives, which costs and environmental consequences may differ. This paper presents the results of a research project that aimed to develop a method for the ecological and cost-based selection of supply concepts.
ecological rating, supply concepts, green logistics
The production ramp-up is often a critical period for manufacturing companies. It is essential to prepare an efficient plan and to monitor consistently the abidance of this plan. With a maturity level model and key figures the quality of a ramp-up can be described. Therefore, the values of the key figures are categorized into maturity levels. By different aggregation levels a target-actual comparison can be made based on one key performance indicator.
production ramp-up, maturity model, aggregation logic, ramp-up management
The production ramp-up is often a critical period for manufacturing companies. With a developed method for planning and monitoring of production ramp-ups at new locations this critical period becomes manageable. The method consists of reference processes, key figures and reactions. By different aggregation levels a target-actual comparison can be made to identify appropriate reactions.
production ramp-up, maturity model, aggregation logic, ramp-up management
By leveraging the production factor "human" it is possible by taking into account human performance fluctuations during the day to reduce product-related defect costs and increase quality. To this end, the integration of human performance variations in methods of production planning and control must be carried out. This article introduces a method by which a quality-oriented job shop schedule can be created, taking into account human performance fluctuations.
produktion planning, job shop scheduling, human performance fluctuation, optimization problem
The assembly of complex, large-scale products is often characterized by poor date availability, limited process standardization, frequent product modifications and flexible usage of resources, which often leads to interruptions in the assembling process. Therefore, in a research project between the IPH Hannover and the WZL of RWTH Aachen University, a methodology for assembly processes is developed which allows the identification and evaluation of process alternatives in case of interruptions. For the evaluation of those process alternatives logistical objectives are used.
xxl-product, adaptive assembly scheduling, interruption assembly process, logistical objectives
The production ramp-up is often a critical period for manufacturing companies. It is essential to prepare an efficient plan and to monitor consistently the abidance of this plan. Generally processes and activities can be monitored with key performance indicators. This article describes an approach to identificate key performance indicators for the monitoring of additional production capacities at new locations.
production ramp-up, maturity model, aggregation logic, ramp-up management
When designing delivery concepts, companies often have a choice between different alternatives. The decision between these alternatives is no longer made only on their costs and logistical efficiency. Rather the ecological compatibility of the processes is more and more considered. This paper introduces ways to integrate environmental sustainability into decision-making.
ecological evaluation, delivery concepts, green logistics
The energy costs‘s share in the total is increasing in producing companies. Due to variations in the energy consumption over the day, arising power peaks lead to high energy costs. Power peaks could be reduced by load management systems. But these systems could have a negative impact on logistic performance figures. A simultaneous optimization of logistic performance figures and the energy consumption is not available yet. In this article a method for the energy cost-based production scheduling is presented. This method schedules jobs on machines in a way that the energy consumption is equalized and the logistic performance (makespan, stock, job delays, workload) is ensured.
energy costs, power peaks, production scheduling
The energy costs‘s share in the total is increasing in producing companies. Due to variations in the energy consumption over the day, arising power peaks lead to high energy costs. Power peaks could be reduced by load management systems. But these systems could have a negative impact on logistic performance figures. A simultaneous optimization of logistic performance figures and the energy consumption is not available yet. In this article a method for the energy cost-based production scheduling is presented. This method schedules jobs on machines in a way that the energy consumption is equalized and the logistic performance (makespan, stock, job delays, workload) is ensured.
energy costs, power peaks, production scheduling
Student job, Internship
Student job, Internship
