Although estimating the cost of a software project and the effort involved is very important, improving accuracy and establishing the software as a technology are both difficult. To solve these problems we have tried to use a software estimating tool. This tool has two characteristics. The first is that the tool uses function point analysis (FPA) instead of source lines of code, and the second is that special factors present in software development (usually estimated only from experience) are considered. This report provides some examples of how software project effort estimates can be improved.