The make or buy decision is a strategic issue. When looking for finding out which components or products should be manufactured in house or ex-ternalized, questions about the required human and technical resources as well as costs of the externalization are to be answered. In the case of mobile manufacturing systems that are movable between various locations, long term strategic considerations must be considered when addressing the make or buy decision problem. This paper aims to provide a structured make or buy decision model, adapted for reconfigurable manufacturing systems with strong mobility constraints. Industrial application case is provided to illustrate the presented method.