Function Point Analysis (FPA) is a method to measure the functional size of an information system. FPA measures the functional size by looking at the (functional) transactions and (logical) data files that are relevant to the user in the business.
The unit of measurement is “function points”; the functional size of an information system is expressed by a number of function points. For example, an information system can have a size of 500 function points.
If the size of an information system or requirements of an information system are known, then these function points can be used to create early project estimates, compare experience figures of finished projects, or for contracting and become a supporting tool in making objective and measurable agreements.
Read more about function points in theme Sizing.