Why do projects fail?

If we made that question to people that do not completely agree on what a project failure is, the thoughts we may gather about how a failure is determined would be inconsistent each other. Most likely.
As a matter of fact, the majority of the projects just fail when they go overbudget or have bad quality outcomes. However, it is not unusual to see projects in delay or consolidating extracosts which are still considered a success by the stakeholders.
So, let's try to go beyond, There is more than the mere mention of the most common triggers of a project failure.

First of all. When can we talk about a failure for a project?

As said, there might be multiple opinions about that. In my view, a project fails when it does not meet stakeholders expectations and their interests.

The expectations of a project are those that all project management bibles invite to take into account while leading a project.
They are usually written black on white on the project charter and on the project documentation: quality and technical requirements, budget, delivery dates.

Sometimes, the real interests of the stakeholders may be hidden to most of the organizational functions...and that's a challenge for the project manager: the real expectations may not necessarily match with what is inside the project requisition. A smart project manager should look at the requirements of course, but also to other areas to have the big picture and fully understand the context. Organization growth, program success, market expansion is where to focus on in order to get the real critical-to-success parameters.

In other words, a project may be on schedule and within budget and still be suddenly suspended or canceled, if stakeholders do not find anymore a strategic interest in keeping it active.

In contrast, a project may be in delay, over budget or not in full compliance with the technical requirements and yet be successfully brought to conclusion with full appreciation of the stakeholders.
A seasoned project manager needs to understand that it is worth to spend efforts here and there based on the real interests of his project, they will be the real drivers to leverage on to have resources and obtain the sponsorship to deliver till the last day.
Is failure an option?
We are used to hear big slogan like "failure is not an option!".
I prefer to consider a failure just as a possible scenario, more than an option or not. It  sounds just unrealistic that the stakeholders of a project would even consider the failure as a viable option to pursue (or otherwise to discard).
Either way, projects fail sometime.
Why do project fails?
For tens of reasons and it is not difficult to shed some light on the most common drivers we need to face every day.
A project may fail because of the following (including but not limited to):
  • individuals' faults, lack of experience, not trained employees, wrongdoing etc.
  • poor coordination, unresponsiveness, experimental approaches
  • organization, including contractors, is not mature enough to bear the project.
  • unplanned and unexpected events that interfere with project execution.
  • force majeure, like a tornado which causes a stop to all the activities of a campus or a second world war dangerous item found in the parking area of a supplier during a refurbishment. You never know what can happen until it happens.
  • repeated, multiple and late changes to the requirements. Changes can be a tremendous opportunity to increase your project budget, but also a solid reason to disrupt your execution even if it was diligently started.
  • underestimated complexity, including wrong assumptions in design reviews and during internal feasibility studies.
  • funding issues, like a missing or strongly delayed payment, bankruptcy etc..

In this connection, I would encourage the readers to download the paper offered by NASA here, as they have done interesting internal studies about project management excellence and in particular about the potential drivers of a project failure. Also, guidelines to be adopted are suggested.
In this article, I just wanted to briefly emphasize the main triggers for a project failure. There is much more to say and I let you comment my post to share experiences and thoughts.