  Reliable effort estimation remains an ongoing challenge to software
engineers. Accurate effort estimation is the state of art of software
engineering, effort estimation of software is the preliminary phase between the
client and the business enterprise. The relationship between the client and the
business enterprise begins with the estimation of the software. The credibility
of the client to the business enterprise increases with the accurate
estimation. Effort estimation often requires generalizing from a small number
of historical projects. Generalization from such limited experience is an
inherently under constrained problem. Accurate estimation is a complex process
because it can be visualized as software effort prediction, as the term
indicates prediction never becomes an actual. This work follows the basics of
the empirical software effort estimation models. The goal of this paper is to
study the empirical software effort estimation. The primary conclusion is that
no single technique is best for all situations, and that a careful comparison
of the results of several approaches is most likely to produce realistic
estimates.
