With a lighthouse project, a model project is meant that aims besides its original purpose to have a signal effect for numerous follow-up projects as they look towards it for inspiration and guidance. In addition to success, therefore, also a great notoriety is intended. In companies, this is like when changing direction or realignments used (Change Management). The use of the term has been demonstrated since 1980.
The terms milestone and quantum leap are also used with a similar meaning.
References
Lighthouse Project Wikipedia(Text) CC BY-SA