The term "Tjänst" is today used in a large variety of meanings, depending on the area of application. This is the situation both within and outside the Swedish Defence Forces. FMV has therefore asked FOI to perform a study with the subject to describe how the term "Tjänst" (Service) is used in different civilian and military areas of application. The goal was to provide a better understanding of how the term "tjänst" (Senvice) is used in the Swedish Defence. The study was performed by a group with broad knowledge and the term was investigated for areas within and outside the Swedish Defence. The results were presented both at a mid-term assessment with the customer and at two different final seminars; one at FMV and one at the military head quarters. The overall conclusion is that the term "tjänst" is used frequently, but without an explicit definition of its exact meaning. In the present defence organization, new meanings of "´tjänst" is avoided. Instead alternative words such as "funktion" (function) and "förmåga" (ability) is used. Since commercial technology is used to a large extent for the new defence, it is important to identify the relation between the service concept chosen for the defence and the corresponding commercial usage of this term. It is therefore important that such "commercial interfaces" are identified.