Industrial system development is facing an ever growing complexity of the target applications together with market demands of reducing time and costs of products. This issue is even more relevant in safety critical domains, where the quality of the system has to be necessarily validated before any release can be placed on the market. Bombardier Transportation works in one of such domains, namely rail-equipment development, and has to deal with problems related to testing the developed applications in an efficient and effective way while trying to reduce costs and time-to-market.This work illustrates the concrete solutions adopted by the company in order to effectively test their systems; in particular, they adopt automated regression testing and simulated environments to speed-up the process and alleviate the problems due to hardware costs and size as well as the non-reversibility of reality.