There is a long history before the project "Tactical assessment of sensor systems" (TVS) of the need to evaluate a complex technical system in its context of use. The contribution from TVS is to adapt a previously developed assessment methodology, COAT, to also be able to assess sensor systems. This has meant that all parts of the COAT has been updated in terms of definitions, guidelines and templates, and that the methodology for system modeling has changed more radically in order to manage dynamic processes in a better way as a basis for setting performance measures. The method has also gained a better support of different tools, although much still remains to be done in this area. The COAT/TVS method has been tested against two sensor systems that are of interest for FM, which chas onfirmed the method's usefulness, given us a better understanding of the assessed systems, and also given us better insight into the method's properties. We believe that the method can be useful for FM in various ways such as for the evolutionary development, in studies, in the planning of a foreign mission etc. Knowledge transfer to the FM is probably best achieved through courses and mentoring.