Difficulties in Software Cost Estimation:A Survey

It is proved fact that the success of software project depends on the cost estimation done at initial stages of software development process. The project acquisition stage is the one where the detail available to estimator is minimal. The confusion of estimation arises in this stage. All other stages, progressively, increase the detail and hence reduce uncertainty in estimation. However, it is necessary to estimate cost of the software to be produced in the early stages itself. This paper describes different approaches for software cost estimation and their problems and the focus is on what the things that made the estimation is so hard.