Open-Source, 🚗 Industry Compatible?

Open-source CFD software (Open Foam) are in competition with other commercial options (Ansys, Siemens) in the automotive industry. Some companies use open-source with a great success while some others shout it is a disaster. What make the success of an open-source deployment? Are Open-source options completely free? How to plan and to budget deployment of open-sources in your company?