@inproceedings{VitzthumClausHerrmann, author = {Vitzthum, Thorsten and Claus, Thorsten and Herrmann, Frank}, title = {Can Aggregate Production Planning (APP) be modified to be as good as Master Production Scheduling (MPS)}, series = {ACC Journal}, volume = {23}, booktitle = {ACC Journal}, number = {2}, doi = {10.15240/tul/004/2017-2-012}, pages = {155 -- 162}, abstract = {In diesem Beitrag wird anhand einer Fallstudie die Bedeutung der Hauptproduktionsprogrammplanung (HPPLAN) f{\"u}r die hierarchische Produktionsplanung herausgearbeitet werden. Dazu wird versucht das Ergebnis der aggregierten Gesamtplanung (AGGRPLAN) durch Ver{\"a}nderung einzelner Paramater so zu verbessern, dass es dem Ergebnis der HPPLAN entspricht. Im Rahmen der Untersuchungen konnten dabei Verbesserungen f{\"u}r einzelne Planungssituationen erzielt werden, eine generelle L{\"o}sung konnte jedoch nicht gefunden werden. Insbesondere der Einsatz eines geeigneten Kapazit{\"a}tsreduktionsfaktors in Verbindung mit der Ber{\"u}cksichtigung der Durchlaufzeit f{\"u}hrt zu einer Verbesserung der L{\"o}sung. Bei der Planung von mehr als einem Produkt ist allerdings schwierig einen geeigneten Kapazit{\"a}tsreduktionsfaktor zu finden, da dieser abh{\"a}ngig von der Nachfrage ist.}, subject = {Hierarchische Produktionsplanung}, language = {en} } @inproceedings{VitzthumClausHerrmann, author = {Vitzthum, Thorsten and Claus, Thorsten and Herrmann, Frank}, title = {Einfluss von Mitarbeiterqualifikationszeiten im Rahmen nachhaltiger Produktionsplanung}, series = {Simulation in Produktion und Logistik 2017, Kassel, 20.-22. September}, booktitle = {Simulation in Produktion und Logistik 2017, Kassel, 20.-22. September}, pages = {315 -- 324}, abstract = {This research paper evaluates the potential of reducing shortages and costs that are created by training measures as an example for measurement of extended qualification of key employees in sustainable production planning. Capacity planning with standard methods in Enterprise Resource Planning Systems, namely priority rules, are used. Almost always, the optimal solution is not found, although there is one. In addition, unnecessarily high stocks are built up. In real business situations, this causes lost profits.}, subject = {Enterprise-Resource-Planning}, language = {de} } @inproceedings{TrostClausHerrmann, author = {Trost, Marco and Claus, Thorsten and Herrmann, Frank}, title = {Employment of temporary workers and use of overtime to achieve volume flexibility using master production scheduling: monetary and social implications}, series = {Proceedings of the 35th ECMS International Conference on Modelling and Simulation (ECMS 2021): May 31st-June 2nd, 2021, United Kingdom}, booktitle = {Proceedings of the 35th ECMS International Conference on Modelling and Simulation (ECMS 2021): May 31st-June 2nd, 2021, United Kingdom}, editor = {Al-Begain, Khalid}, isbn = {978-3-937436-72-2}, doi = {10.7148/2021-0213}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-24906}, abstract = {Flexibility and in particular volume flexibility is an important topic for industrial manufacturing companies. In this context, the harmonization of the available and required capacity is a central task, especially with increasing fluctuations in customer demand. In classical approaches , this is considered only by the use of additional capacities and there are only a few approaches that combine aspects of personnel planning with production planning. Therefore, this article presents a linear optimization model for master production scheduling that includes aspects of personnel requirements planning. It is used to investigate different strategies for the use of overtime and temporary workers in order to achieve different levels of volume flexibility. With regard to the monetary and social impacts, the results indicate that overtime has a stronger influence to achieve volume flexibility than the use of temporary workers. However, both are affected by substantial deficits in human working conditions. But the results also imply a promising potential for improving the social aspects without a significant increase in costs.}, language = {en} } @inproceedings{TrostClausHerrmann, author = {Trost, Marco and Claus, Thorsten and Herrmann, Frank}, title = {Influence of Company Sizes in adapted Master Production Scheduling for Improving Human Working Conditions}, series = {Proceedings of the 34th International ECMS Conference on Modelling and Simulation, ECMS 2020}, booktitle = {Proceedings of the 34th International ECMS Conference on Modelling and Simulation, ECMS 2020}, editor = {Steglich, Mike}, publisher = {European Council for Modelling and Simulation}, isbn = {978-3-937436-68-5}, doi = {10.7148/2020-0287}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-24817}, pages = {287 -- 293}, abstract = {Sustainability is an important topic in production plan-ning and control. This article contributes in particular the to further research on the social dimension. It pre-sents a linear optimisation model for Master Produc-tion Scheduling in order to improve human working conditions. Existing approaches have already identified a considerable potential for improvements. Further-more, this article analyses the influence of the compa-ny size on workload and costs using an application with a high proportion of manual activities. It is demonstrat-ed that human working conditions can be improved independently from the company size without increas-ing costs. In addition, smaller companies tend to have a higher exhaustion and the workload affects the total costs more in smaller companies. Therefore, smaller companies might benefit more from an improvement in human working conditions.}, language = {en} } @inproceedings{TerbrackHerrmannClaus, author = {Terbrack, Hajo and Herrmann, Frank and Claus, Thorsten}, title = {Deviation in Energy Consumption on Aggregate Production Planning Level in Industry Practice}, series = {Proceedings of the 34th International ECMS Conference on Modelling and Simulation (ECMS 2020)}, booktitle = {Proceedings of the 34th International ECMS Conference on Modelling and Simulation (ECMS 2020)}, editor = {Steglich, Mike}, isbn = {978-3-937436-68-5}, doi = {10.7148/2020-0334}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-24804}, pages = {334 -- 340}, abstract = {In this article, we discuss energy consumption of producing firms on aggregate production planning. While almost constant energy consumption can be the case for a producing firm, highly fluctuating energy demand can occur as well. Together with volatile energy supply, e.g. due to renewable energy sources, this combination of fluctuating energy supply and demand can result in planning uncertainty and high energy costs. We propose different case studies in which such high deviation in the electricity consumption of a producing firm occurs due to aggregate production planning without appropriate consideration of energy consumption.}, language = {en} } @article{TerbrackFrankHerrmannetal., author = {Terbrack, Hajo and Frank, Ingo and Herrmann, Frank and Claus, Thorsten and Trost, Marco and G{\"o}tz, Matthias}, title = {A literature database on ecological sustainability in hierarchical production planning}, series = {Anwendungen und Konzepte der Wirtschaftsinformatik}, journal = {Anwendungen und Konzepte der Wirtschaftsinformatik}, number = {12}, publisher = {AKWI}, issn = {2296-4592}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-23539}, pages = {36 -- 40}, abstract = {This article describes a systematic literature search of research articles on the topics of ecological sustainability and production planning. Over 900 research articles deal intensively with these topics. These articles were catalogued and included in a database. They can be evaluated with an analysis tool, developed by the research group. The tool is available free of charge via a website of the research group.}, language = {en} } @inproceedings{SelmairHanfeldClausetal., author = {Selmair, Maximilian and Hanfeld, Marc and Claus, Thorsten and Herrmann, Frank}, title = {Exploring Opportunities}, series = {Simulation Notes Europe (SNE), Special Issue: Simulation in Production and Logistics: Impact of Energetic Factors}, volume = {27}, booktitle = {Simulation Notes Europe (SNE), Special Issue: Simulation in Production and Logistics: Impact of Energetic Factors}, number = {2}, doi = {10.11128/sne.27.tn.10375}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-2007}, pages = {97 -- 103}, abstract = {Motivated by the increasing share of renewable energy in the markets for energy commodities, this study has evaluated the potential for optimizing production planning by taking into account disposable options for procuring energy, in this case electricity. For this purpose, a material flow simulation study extended by an electricity price simulation has been executed to examine possible cost scenarios. Our findings support the notion of a potential for further research in new optimization models involving energy procurement as well as energy trading options}, subject = {Materialflussplanung}, language = {en} } @misc{EnglbergerHerrmannClaus, author = {Englberger, Julian and Herrmann, Frank and Claus, Thorsten}, title = {A simulation analysis of Independent Requirements Consumption in Master Production Scheduling}, series = {ASIM Workshop, Trends in Computational Science and Engineering (ASIM TCSE 2012), February 13-14, 2012, Vienna University of Technology, Austria}, journal = {ASIM Workshop, Trends in Computational Science and Engineering (ASIM TCSE 2012), February 13-14, 2012, Vienna University of Technology, Austria}, abstract = {This poster presents purpose and function of the Independent Requirements Consumption in Master Production Scheduling and gives recommendations for its application. The approach of hierarchical production planning and its planning problems are explained. The problem of new customer requirements information between planning periods and solving options are shown. The solving option of Independent Requirements Consumption is focus of this poster. The algorithm of the Independent Requirements Consumption that is implemented in commercial Enterprise Resource Planning (ERP) systems like the SAP system is analyzed. The methods for analyzing the effects of the Independent Requirements Consumption are outlined. The scenarios for simulation studies are stated and compared to similar investigations. The simulation studies were performed on a simulation system at IPF that contains both a production planning and control system and a production. The extent of simulation analyses outreaches similar investigations, especially because of the variety of scenarios. For scenarios in which capacity is available to a sufficient extent, advice for setting the Independent Requirements Consumption parameters is given. It is pointed out that with production constrained scenarios, the necessity to level out production leads to problems. An algorithm to determine necessary inventory levels is presented. It is stated that straight advice for Independent Requirements Consumption parameter settings might not be possible with production constrained scenarios. Further analyses with production constrained scenarios as well as investigations concerning safety stocks in combination with Independent Requirements Consumption are current and future research topics at the Innovation Center for Production Logistics and Factory Planning.}, subject = {Produktonsplanung}, language = {en} } @misc{TerbrackClausHerrmann, author = {Terbrack, Hajo and Claus, Thorsten and Herrmann, Frank}, title = {An Optimization Model for Production Scheduling with Energy Consumption and Energy-related Emissions}, series = {OR 2022, International Conference on Operations Research 2022, September 6-9, 2022, Karlsruhe}, journal = {OR 2022, International Conference on Operations Research 2022, September 6-9, 2022, Karlsruhe}, abstract = {Due to the scarcity of resources, rising costs as well as the further need for ecological improvement in industrial production, firms are increasingly motivated to take into account energy consumption in production planning. Associated with this, the consideration of energy-related emissions is becoming an additional point of interest for decisionmakers in both, economic and ecological terms. Based on an extensive systematic literature review, the study at hand presents a multicriterial scheduling problem that addresses tardiness, energy consumption and energy-related emissions in production scheduling. A model is introduced that takes into account job release dates, multiple machine states, a power demand threshold as well as time-varying emission conversion factors. Multiple case studies are analysed and the effects of different technological implementations as energy onsite generation and energy storage systems are evaluated. Furthermore, several price mechanisms regarding energy procurement and emission trading are discussed. Moreover, by coupling the optimization model to a discrete event simulation model, we are able to compare the model results to real case scenarios. First computational experiments have demonstrated that the model and its extensions can effectively reduce the environmental impact associated with production while simultaneously considering corresponding economic objectives. Based on the proposed approach, our research aims on answering the question with which economic trade-offs an ecological improvement in terms of energy consumption and emission output can be achieved in production.}, language = {en} } @misc{HerrmannSchoenClausetal., author = {Herrmann, Frank and Schoen, Maximilian and Claus, Thorsten and Dai, Chenghao}, title = {Aggregate Production Planning under Risk of Disruption}, series = {OR 2024, International Conference on Operations Research 2024, September 3-6, 2024, Munich}, journal = {OR 2024, International Conference on Operations Research 2024, September 3-6, 2024, Munich}, abstract = {In recent years, large scale disruptions to global supply chains, like the Covid pandemic, a ship blocking the Suez canal or sanctions against Russia, have caused production to slow down or even to stand still, causing shortages and massive losses for affected businesses. Even if only specific companies were originally affected, shortages and delays rippled along the supply network. The established approach to deal with disruptions is to utilize safety stock and capacity to compensate for fluctuations in uncertain quantities like customer demand. This approach is tried and tested for small fluctuations. To address larger disruptions, like the above given, very high safety stock and capacity would be needed, which would lead to unnecessarily high costs. Resilience has often been viewed as an expensive capability that drives costs. Recent studies however advocate for the development of lean resilience concepts, creating new capabilities, which enable resilience and can deal with large fluctuations, reimagining resilience from the perspectives of efficiency and value creation. This contribution identifies gaps in current research and establishes structural deficits of approaches discussed in the literature regarding supply chains. Firstly, the need for rigorous, quantitative definitions of resilience and relevant disruptions is justified. Then, a stochastic model for aggregate production planning that includes capabilities to compensate for such large fluctuations along several dimensions is proposed. Lastly, this model is then applied to a case study pertaining to a realistic supply chain under the risk of large scale disruptions and the results of this approach are evaluated.}, language = {en} }