Project management is a science and not just a boss on the site directing subcontractors. It begins with design and understanding the goals of the overall project. It then morphs to oversight of the project, documenting the construction process and creating reports on that progress. When the C/O is issued that's still not the end of the job. There is still the finale of turning over the systems to those who will use them. This "Commissioning" portion of the project and final step is crucial in assurring the efficiency of systems in the building(s) and longevity of life.