Project managers are deeply involved in this process. They need to help other areas of the company both see and put into effect simple project management processes. This will allow other areas of the company to consistently account for resources and use those resources realistically.
In this economy, everyone is trying to save money by getting the most from small teams. BRM helps companies do this. But, board and senior managers need to be educated first before a project manager can begin instituting the project management model. They need to know how project management works and how it is applicable to other departments.
Also, whoever is going to be in charge of the line needs to have input into the process. This way, the line manager can see the process and see how the process should be progressing. The goal for BRM education should be to educate all upper management personnel so that they readily adopt the project management model and embrace the organizational changes necessary to implement BRM.