When talking about Light House Projects this means nothing less than that a small sector of your organization e.g a department is already turned around. By that we are talking about living already the ideal state, that you defined for the complete organization.
Processes and structures can be seen as guidance for your organizations’ lean journey. It provides directions, shows what is possible and therefore is the kickstarter for a successful roll-out as people can convince themselves with their own eyes.
Just keep in mind that the lean journey with its process of continuous improvement is never over. The pioneer has to lead the way.