experience, what is the TOP #1 cause for Project failure? From experience, the following are the TOP10 causes of Project failure that Mathew can think of (they are not in any kind of order): #1. Lacking Sponsor 's Involvement/Ownership #2. Halo Effect (Wrong Man for the Job) #3. Poor HR Management #4. Poor/Inadequate Project Communications #5. Ignoring Project Stakeholders #6. Absence of Risk Management #7. Scope Creep/Unrealistic Expectations ( scope creep: Frequent and uncontrolled changes