Human Robot Collaboration is seen as a significant feature of Industry 4.0 implementation. Collaborative robots (cobots) are supposed to deliver superior process performance, which was so far achieved through the application of Lean Manufacturing techniques. The following case study built around the assembly process of a pneumatic cylinder, tends to analyse not only the actual benefits of cobot implementation, but also the success factors, in conjunction with Lean Manufacturing usage. Finally, this paper suggests a draft method towards the successful integration of cobot.