Purpose: The purpose of this study aims to increase the understanding of which wastes and bottlenecks affect production flows in a customer order-driven environment. To address the purpose, four research questions were formulated:

·      What bottlenecks can be identified in production flows?

·      What improvement measures can be proposed to reduce identified bottlenecks in production flows?

·      What flow-related waste can be identified in production flows?

·      What improvement measures can be proposed to reduce identified waste in production flows?

Method: The study was conducted as a case study using a mixed methods approach, where empirical data was collected through triangulation of semi-structured interviews, observations, and document studies. Both qualitative and quantitative data related to cycle times, takt times, capacity, order inflow, and operational experiences were analyzed in relation to the study’s theoretical framework, including Lean production, Theory of Constraints, and production flow theory.

 Results: The findings show that variation in order inflow, material availability, and information flow creates instability in the production flow. Configuration and burn-in were identified as the system’s main bottleneck, although the primary challenges were related to variation, planning, and information flow rather than inefficiencies within the bottleneck itself. In addition, waiting, unnecessary motion, defects, and underutilization of employee competence were identified as major forms of waste. The findings further suggest that standardized work methods, improved information flow, and more stable planning can contribute to a more balanced and efficient production flow.

 Implications: The study demonstrates that improving production flows requires more than increasing the capacity of the bottleneck resource alone- Instead, the findings highlight the importance of reducing variation, improving coordination, and creating standardized work procedures throughout the production system. The study may provide practical guidance for organizations seeking to improve flow efficiency and reduce waste in customer order-driven production environments.

 Limitations: The study is limited to a single case company and focuses only on internal production flow. Furthermore, the study analyzes the current state and proposes improvement measures without implementing them, which limits the ability to evaluate the long-term effects of the proposed changes.