7 Reasons Megaprojects Fail

via Megaprojects and Risk

1. Scope changes significantly over time.
2. Long planning horizons and complex coordination requirements.
3. Planners lack domain expertise and often quit before their work is done.
4. Decision-making involves multiple stakeholders, public and private, with conflicting interests.
5. Designs are often non-standard, leading to a "uniqueness bias" that impedes learning.
6. Planners overcommit to a project concept at an early stage, resulting in “lock-in” and late stage escalations.
7. Unplanned events are often unaccounted for, leaving budget and time contingencies inadequate.