A robust enterprise system will enable companies to simplify their business process to achieve thespeed, efficiency and flexibility that are so fundamental for market survival. But implementations ofsuch enterprise system and their assimilation into the organizations seems to be very tricky and veryoften unsuccessful. The reasons are many, because it is not just the system that is new, but also theprocesses, collaboration patterns and job roles. However it is safe to say that the failures are not justdue to the technology, but also due to the inappropriate change management in connection with anintroduction of a new enterprise system.This bachelor thesis is aiming to identify, describe and explain the conditions contribution to asuccessful change management triggered by an enterprise system implementation process. This thesisis based on a case study in a large global pharmaceutical company that has embarked on a journey totransform their business processesThe most important conclusions resulted from this case study are that change management isabsolutely essential for successful assimilation of an enterprise system by the organization and thecase company is very well aware of it. The conditions that indicate the successful change managementare increased efficiency, simplified business processes, improved cross-functional collaboration, andhigh user satisfaction.