Recently, I have done research into finding a faster but still reliable way to calculate software sizing. The IFPUG Function Points method was developed over 30 years ago with the focus on accurate and reliable results. Software measurement is a necessity however most analysts agree that it takes a lot of time.
PRICE® TruePlanning™ offers many different calculator options for software sizing. The Function Point calculators include COSMIC Function Points, Fast Function Points, Function Point from RICEFW Objects, Functional Size, IFPUG Function Point, Source Lines of Code (SLOC), and Use Case Conversion Points. More recently, the Simplified Function Points (SiFP) calculator has also been added to TruePlanning™.
The Function Point Methodology is used for measuring software size. Function points help estimate project costs. The Simplified Function Points method was developed to reduce the time it took to calculate the size, while still being an accurate level of measurement. It can be used in place of IFPUG Function Points because they were designed to be equivalent in terms of numerical results.
IFPUG Function Points are made up of different resources that affect it. These resources are Internal Logical Files (ILF), External Interface Files (EIF), External Inputs (EI), External Outputs (EO), and External Inquiries (EQ). Within each of these main categories, the user determines the level of complexity and this affects the weighting factor that is chosen. For example, if a user has an application type of a Human Resource System and wants to use IFPUG Function Points, they will enter their information into the calculator like seen below:
Instead of having to enter all this information, users can choose Simplified Function Points to calculate faster. One of the main differences is that with IFPUG Function Points, weights are computed for each function and with SiFP, weights are fixed. The two components needed for SiFP are Unspecified Generic Elementary Process (UGEP), and Unspecified Generic Data Group (UGDG). UGEP is the number of elementary processes, without considering primary intent. UGDG is the number of logical data files, without considering if they are internal or external. External Inputs, External Outputs, and External Inquiries are counted as UGEP while Internal Logical Files and External Interface Files are both counted as UGDG.
We can take the same Human Resource System example from earlier and calculate using Simplified Function Points instead of IFPUG Function Points like shown below:
This example helps to show that Simplified Function Points allow the user to enter much less information, while still ending in the same result. It is calculated through a simple and easy to use formula of of (4.6*#UGEP)+(7*#UGDG).
Look for this Simplified Function Points calculator in the next update of TruePlanning™.