This work presents design solution of a device used for module assembly of a low-floor electric minibus. The device will primarly be used to assemble the minibus bearing structure (shell) which consists of three segments and is manufactured out of composite materials. Additionaly the device enables the bearing structure to be connected with the front (steering) and rear (drive) modules. The first part of this paper explores existing devices with similar purpose in production lines in the automotive industry. In order to reach the optimal design solution the list of demands regarding the structure of the device was made, as well as defining the functionality of the device. The method of function decomposition was applied to resolve the device functions into subfunctions for which feasible solutions were suggested. Upon these suggestions and the list of demands three concepts were presented, considering maximal possible adaptibility to differing dimensions and shapes of the vehicles and ease of vehicle unmounting. The optimal concept was described in detail while seeking to achieve maximal possible device seperability as well as using components avaliable on the market.