During the development of the software, Software Requirement Changes (SRC) often occurs. Software estimation helps in maintaining a balance between the increase and decrease of the price, time, etc. Function Point Analysis (FPA) is a software effort estimation technique used for measuring the size and complexity of software by calculating the functionality from a user's point of view. Function count focuses on what functionality is being delivered. It enables programmers to perform function point counting themselves instead of contacting an expert. An empirical study has been conducted to analyze the capability of the FPA technique. The results of the FPA-SDP (Function Point Analysis for Software Development Phase) model can help software project managers in (i) knowing the inconsistent states of software artifacts (ii) estimating the actual size of a change request with its complexity level for the software development phase.