Project managers often report a 90% completion rate for long periods, which frequently leads to project delays. Research by Haralambos Iakovou, Ron Thompson, and Jeff Smith published in MIS Quarterly in 2009 identifies five organizational factors that contribute to this optimistic status bias.
Capers Jones found that IT project requirements grow by an average of 2% per month from the end of initial requirements gathering until testing begins. This growth ranges from 1% for outsourced development to 3.5% for commercial products, making it difficult to account for all tasks at the start.
A study by Ford and Sterman documented two microchip development projects. One was planned for 34 weeks, reached 79% completion at the deadline, and finished at 81 weeks. The second was planned for 39 weeks, showed 73% progress at the deadline, and finished at 69 weeks.
Manual calculation of project progress often leads to errors and subjective reporting. Automated tools, such as Naumen Project Ruler, calculate progress by aggregating subtasks, tasks, stages, and epics, which helps eliminate the bias inherent in counting only the number of completed tasks.
Progress metrics only indicate past performance and cannot reliably predict completion dates. To improve forecasting, managers should distinguish between completed work and the remaining uncertainty, such as unverified integrations or pending information from cross-functional teams.
