This thesis analyzes the cleaning tool fulfillment process at ROSEN Europe B.V. and identifies how preventable internal delays can be reduced. Cleaning tools are essential for preparing pipelines for inspection. The current fulfillment process, however, regularly faces inefficiencies. Weekly, 36% of cleaning tools are delivered with an internal delay, which increases complexity, reduces efficiency, and affects the reliability of planning. To understand and improve the process, this research applies process modeling and root cause analysis. The current fulfillment process is visualized using Business Process Model and Notation (BPMN), which provides a clear overview of task dependencies and interactions between departments. Semi-structured interviews with employees from six different departments create insight into recurring issues. A Fishbone Diagram and the Five Whys technique are used to analyze these findings and identify the underlying causes of the main problems. The analysis shows three main problem areas: parts are not available when required, incorrect parts are delivered, and workshop tasks cannot always be executed efficiently. These problems result from root causes such as late Tool Preparation Sheet (TPS) customization, incomplete or incorrect pipeline data, manual checks, a two-eyes principle, unclear assembly priorities, and the absence of registration for parts on returned tools. Cross-cutting issues, such as weak prioritization of revisions, unstrategic order acceptance, and inconsistent archiving of gauging run data, reinforce these problems. Based on these insights, this thesis proposes ten improvement opportunities. These opportunities strengthen the foundation of the process, improve collaboration between stakeholders, and build lasting reliability in the workflow. Together, they support ROSEN in reducing preventable internal delays and creating a structured basis for continuous improvement.