Why projects fail?

In Programming world , you always see unsatisfied customers and developers.
After years of development I can understand a project will fail or not from beginning
if there are some signs like below.

1) Low price
Projects specs are announced and price is asked to companies.And then companies bid for lowest price.
What is lowest price? Can you afford to make a project will 2 juniors instead of 1 senior?
1 2 3 or whatever Junior is not one senior.
There is no replacement in programming.

2) Who knows the industry?
Programmers often underrate project domain. They think most important thing in project
is technical part. I never see a big project where domain knowledge is not important.
Programmers must respect domain knowledge and understand it as much as they can.

3)Unclear breakpoints.
At 1st stages people code fast and come to a stage.
At that stage ,customer says this is not what we want.

Will you continue with problematic logic?
Can you afford a re-write?

Program plan must have some milestones and specs to reply
these questions.



My simple rule for a project :

A project will fail or will be in a low quality :

If there is no one int the team who has done a technical similar project