In PM Network-March 2019, PMI identifies four factors for complete and accurate project estimation. The article cites several construction projects where the estimation lifecycle resulted in increases in cost from early deliverables. While the factors are somewhat expected, the most impactful to the skill levels on estimation professionals and the quality of deliverables is the first - learn the business inside and out. This reference is not to be confused with the certifications, knowledge of the process, skills with software tools or a portfolio of deliverables. It is about knowing the business domain for the project scope of the estimation, such trade jurisdictions and labor crafts, means and methods, procurement practices, work restrictions, sequence of system construction, regulatory requirements and the commissioning and turnover of the project for operations.