The primary purpose of software estimation is not to predict a project's outcome; it is to determine whether a project's targets are realistic enough to allow the project to be controlled to meet them.
Steve McConnellSoftware projects fail for one of two general reasons: the project team lacks the knowledge to conduct a software project successfully, or the project team lacks the resolve to conduct a project effectively.
Steve McConnellThe default movement on a software project should be in the direction of taking elements of the software away to make it simpler rather than adding elements to make it more complex.
Steve McConnell