- The IPH
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 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
In 2022 germanys last nuclear power plants will be shut down. In addition to the decision to phase out nuclear power a worldwide shortage of fossil fuels will lead to a steady rise in energy costs. Therefore the IPH develops procedures and methods, which will help companies to reduce their energy costs.
energy costs, occupancy plan, energy consumption