Purpose - Planing mills represent a later value‑adding stage in sawmill production, where variation in raw material and a broad product mix create complexity. Despite this, the understanding of the setup process in planing mills is limited. Since long setup times negatively affect capacity, flexibility, and lead time, there is a need to map which activities drive setup time and how it can be reduced within planing operations. The purpose of the study was therefore formulated as follows: The purpose is to increase the understanding of the setup process on a planing line in a sawmill and to investigate the possibilities for reducing setup time. To fulfill the purpose, the following research questions have been formulated:

[1] Which activities are included in the setup process on a planing line, and how do they contribute to the total setup time?

[2] Which improvement proposals can be identified to reduce setup time?

Method - The study was conducted as a case study at a sawmill. Data collection was based on triangulation consisting of interviews, observations, and document analysis. This methodological approach was deemed appropriate for answering the study’s purpose and research questions.

Findings - The activities included in the setup process could be divided into four overall categories. Most of the activities were carried out while the planer was turned off, which was necessary for safety reasons. The time distribution showed that test runs and post‑adjustments accounted for nearly half of the total setup time. This was caused by variation in work methods, sawn timber output, and tool wear. The study also showed that tool availability varied, which resulted in time spent searching for tools. Based on these findings, the improvement potential is primarily found in enhancing tool management. Therefore, implementing 5S can create better order and structure.

Implications - Theoretically, the study showed that production environments with high variation influenced how established methods for reducing setup time could be applied in practice. The results clarified that these methods needed to be adapted to the complexity and variation of the production environment rather than being treated as generic solutions. Practically, the study showed that 5S, visual standards, and clear routines for tool management could reduce unnecessary searching and thereby decrease setup time.

Delimitations - The study was limited to a single planing mill and therefore did not include other parts of the sawmill. Furthermore, the study was delimited from changes over time and was conducted from an operational perspective. 

Keywords – Setup time, setup time reduction, planing mill, Single-Minute Exchange of Die (SMED), 5S, waste.