What is the main reason that projects fail?

عدم اختيار الشخص المناسب فى المكان المناسب وضعف الخطط وعدم وضوح الاهداف

Indeed, there can be so many reasons for project failure.
But in my book all those reasons fall under 1 simple sentence: Failure to adequately identify, document and track requirements.

There can be many reasons for a project failure..
some of them can be as follows: -Wrong business requirements (its not something what company wants) -Lack of solid and realistic plan and business case (Estimates for cost and schedule are erroneous) -Poorly defined roles and responsibilities + weak team -No change control process -Lack of prioritization and project portfolio management -Insufficient resources (funding and personnel) + internal politics -Ignoring project warning signs, testing and wrong and emotional decisions These are few of the major ones I can think of now..
hope it helps.
thanks,

the main reason for project failure is the bad planning if u fail 2 plan then u plan 2 fail

From my point of view, projects tend to fail due to eithr or all of the following; 1.
The lack of clear defined goal(s) &objective(s) of the project 2.
The absence a shared vision & mission 3.
The in-approporiate mix of the project team players (based upon their competencies & cababilities) 4.
The absence of a named project owner 5.
The absence of time-framed project plan bound by time frames & dead-lines 6.
The presence of conflict of interest or isolated islands with in the same team 7.
The lack of a review process for the project development 8.
The lack of clear communications channels through which the project team can communicate 9.
The lack of suffiecient resources (based upon the lack of planing) 10.
The lack of crisis-management S.O.Ps

1)- Doing a project just to do without any passion; 2)- Starting without any market research or doing a market research without any scientific criteria; 3)- Conduct a project without taking into consideration the real need of the target; 4)- No leadership identified; 5)- Doing a project just for money; 6)- Avoiding social responsability; 7)- Not thinking out side of the box; 8)- Problems = Avoiding = No real solution = Missing the real entrepreneurship spirit

I want to add to all the previous valuable comments resistance to change.
Any project manager should involve all stakeholders to decrease their resistance to change and this by bridging the gap between them.

الادارة الفاشلة والتخطيط الفاشل والتنفيذ الفاشل مجتمعة أو أحد هذه الأسباب ففشل احدهم هو فشل المشروع ككل .

A project is considered a failure when it has not delivered what was required, in line with expectations.
Therefore, in order to succeed, a project must deliver to cost, to quality, and on time.
Reasons for Project Failure can be a lot: - failure Quality, cost, time.
- Governance is poor - Implementation is poor - Business case is poor - impossible to deliver the business case - environmental changes....etc For a project to be successful, it's not enough simply to manage your project competently, and deliver a good quality product.
To avoid failure, make sure you have identified the right business requirements, created an achievable business case, put strong project governance into place, managed a high-quality implementation, focused on benefits, and monitored your changing environment.

Projects usually fail for these reasons...
1) Lack of plan is plan to fail.
2) Too many chef's spoil the soup.
(lack of good leadership) 3) Clients intervention to the Maximum...
this can be really annoying.
4) Wrong people to do the right job.
5) Sudden lack of resources.
6) Hiding the dirt under the carpet...
not testing extensively and later on faced with huge irreparable problems...
Hope you find them helpful and avoid them.
Cheers

Since the success or a failure of a project is a result of a team work, hence Madina Kortoeva and Mohammed Hamza Sheikh are right and we cannot say any reason the main