Background: Chronic obstructive lung disease (COPD) is a very serious and common chronic condition. Not all patients having COPD are referred to rehabilitation even though they can benefit from rehabilitation initiatives. Scope: The overall objective of this research project is to ensure referral and uptake for COPD rehabilitation. We focus on detangling the processes in the cross-sectorial workflow of patients with COPD to understand why most patients are not referred to rehabilitation. Methods: We used the functional resonance analysis method (FRAM) to map referring routines from hospital to municipality. We furthermore facilitated cross-sectorial relational coordination by establishing local-and cross sectorial network groups. Results: We found that staff at the hospital and the municipality had different understandings of what rehabilitation is, and they used different words for the same services. Furthermore, hospital staff lack knowledge of what the municipality has to offer patients with COPD. The network groups revealed flaws in the referral system which needed to be adjusted. Conclusion: The FRAM analysis showed how the work was done in real life and detangled factors important to the collaboration. Based on the FRAM the municipality and hospital had a workshop where they agreed to on activities that should be set up to improve the cross-sectoral relations. This resulted in a simplified referral procedures, however ongoing adjustments are made continually based on recommendations from the network groups.