Executive Level Non-Support. All executives must stand behind the project plan if it can have any chance for success.
Improper Staffing. I have never seen a project succeed when overtime is pre-scheduled into the plan. Outside resources or consultants are the best alternative when in-house staff resources are inadequate.
Poor Project Management. Very few skilled managers ever get the opportunity to manage a project from inception to completion. As a result, most assigned project managers lack the experience in handling the broad range of problems that arise during the course of a project.
Unreasonable Completion Dates. [M]anagement in its wisdom will declare target completion dates, or worse…deadlines, even before a project plan is constructed.
Poor Project Planning. While many tools exist to assist in this process, it is the analysis of an experienced project manager that is needed to develop the plan and smooth out its deficiencies.
The list is a good start, but a broader set of drivers should include issues related to business case, change management, and vendor relationships just to mention a few.
Given the diversity of IT projects, it's hard to create an exhaustive list of conditions that cause projects to fail. Still, we can definitely say most projects crash due to business, organizational, and political reasons, rather than for technology reasons. Despite being an easy target, technology is rarely the real, underlying culprit causing projects to fail.