Non-Functional Requirements and COSMIC Sizing Practitioner’s Guide

Abran, A., Al-Sarayreh, K., Lesterhuis, A. (eds.)

The COSMIC method measures a ‘functional size’ of software based on functional user requirements (FURs). COSMIC-measured functional sizes are mainly used in:
• Estimating project effort , e.g. where project effort = (new software estimated functional size) / (productivity from previous similar projects);
• Measuring and comparing performance across projects of similar characteristics, e.g. using ‘productivity’ = (software functional size)/(project effort).

The purpose of this guide is to:
• Illustrate that system non-functional requirements (system-NFRs) may be allocated in projects as software functional user requirements (software-FUR);
• Demonstrate how to specify and measure, using COSMIC Function Points, the functional size of software-FURs that were system-NFRs; and
• Provide an illustrative example.