Using Function Point Analysis and COSMIC for Measuring the Functional Size of Real-Time and Embedded Software: a Comparison

Function Points Analysis and the COSMIC method are very often used for measuring the functional size of programs. The COSMIC method was proposed to solve some shortcomings of Function Points, including not being well suited for representing the functionality of real-time and embedded software. However, little evidence exists to support the claim that COSMIC Function Points are better suited than traditional Function Points for the measurement of real-time and embedded applications. To help practitioner choose a method for measuring real-time or embedded software, some evidence of the merits and shortcomings of the two methods is needed. Accordingly, our goal is to compare how well the two methods can be used in the functional measurement of real-time and embedded systems. To this end, we applied both measurement methods to the situations that occur quite often in real-time and embedded software and are not considered by standard measurement practices. Our results indicate that, overall, COSMIC Function Points are better suited than traditional Function Points for measuring characteristic features of real-time and embedded systems.