Abstract
Complex product and production systems often result in high variability in the production flow, prohibiting the sustainable implementation of lean practices. In this paper the authors introduce a PDCA cycle to analyse and reduce variability in value streams. The value stream is divided into zones, which are then qualified as stable or unstable. Lean practices can be applied in stable zones, unstable zones remain expert-driven. Measures are introduced to reduce variability in unstable zones with the ultimate target, to turn them into stable zones, extending sustainable lean activities in the value stream, step by step. An IT system is developed to acquire, process and visualise the vast amount of data to provide structured information for experts and management for the reduction of variability in production.
Data availability statement
Due to the nature of this research, the companies did not agree for their data to be shared publicly, so supporting data are not available.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Additional information
Notes on contributors
![](/cms/asset/fd970e0c-5c6e-4f5d-a940-c3d324887bd5/tprs_a_2111614_ilg0001.gif)
Ralph Richter
Dr. Ralph Richter jointly heads the Institute of Production Systems (IPS) with Prof. Deuse. He was a plant manager for Bosch in the USA and Germany, responsible for the areas of consumer goods and automotive supply. In a central role, he was responsible for the design and global roll-out of the Bosch Production System and finally for the design and implementation of a roll-out strategy for Industry 4.0 in an automotive division.
![](/cms/asset/c0e62c56-41c5-4949-bec8-35121a1fef7b/tprs_a_2111614_ilg0002.gif)
Marius Syberg
Marius Syberg, M. Sc., works as a Research Assistant at the Institute of Production Systems at TU Dortmund University. His work focuses on the optimisation of production systems in the context of dynamic value stream analysis, the strategic introduction of Industry 4.0 and the digitalisation of manufacturing companies.
![](/cms/asset/52beade0-b187-4eca-8244-c74ab5ef445f/tprs_a_2111614_ilg0003.gif)
Jochen Deuse
Prof. Dr. Jochen Deuse is head of the Institute of Production Systems (IPS) at the TU Dortmund and a professor at the University of Technology Sydney (UTS), Faculty of Engineering and Information Technology, School of Mechanical and Mechatronic Engineering, Centre for Advanced Manufacturing (CAM).
![](/cms/asset/2a4c6c57-c27a-460f-b429-30d960baa0ba/tprs_a_2111614_ilg0004.gif)
Peter Willats
Peter Willats, M.A., has been a Visiting Professor at the University of Buckingham and founded a research group at TU Dortmund University that develops operations management solutions for complex, mission-driven sectors, such as industrial equipment and healthcare. In this capacity, he lectures at the university and academic and management conferences around the world.
![](/cms/asset/e0b23858-a2df-49ae-8085-dd8dbfb76f20/tprs_a_2111614_ilg0005.gif)
David Lenze
David Lenze, M.Sc. works as a Research Assistant at the IPS and has been leading the Production Systems Dynamics research area since 2016. His substantive focus is on the design of new and optimisation of existing production systems in numerous industrial projects, and his doctoral focus is on the development of a simulation-based methodology for buffer design.