The success of any project relies on many things. While a strong project manager is a key element in any project realizing its expected results, ultimate success also relies on the organizational project management maturity of the company.
As a result, companies need to expand their thinking beyond the idea that the project manager alone is the key to success. The combination of the project manager and the company’s project management ability forms the “complete picture” of a project reaching fruition.

Source : Project Management Competency Development Framework, PMI®
