As Saad has mentioned I feel for most companies matrix based organization would be the most beneficial. I say this because your resources (employees) do not become redundant and the project manager can hand pick individuals from different departments within the company for the specific project that is at hand. This will allow for better communication throughout the departments and will allow everyone to get a chance to work with each other. As a project manager you can consult with your functional head for key issues you may be on the fence about. Although the organization type is important to the company I feel what really dictates a company’s success is ensuring your employees are qualified individuals that can keep an open line of communication.

-Ansel Ueshiro