In a recent IEEE Software article*, the authors (Christof Ebert and Hassan Soubra) provide a comprehensive overview of estimating techniques for software maintenance. In particular they focus on the use of functional size measurement (FSM) as a key parameter for successfully estimating a software project.
What may be most refreshing about the article is the candid observations made regarding the realities of project estimating. For example, they make note of the fact that estimates are often confused with goals or plans and failure to understand the gaps among goals, plans and estimates is often the cause of failure. Additionally, they note that FSM can be "tedious and time-consuming" for organizations with a larger number of projects to measure and go on to introduce a selection of automated tools that support FSM.
The article also does a nice job of introducing the COSMIC method of measuring software’s functional user requirements (FUR) for both the business and real-time applications. This supports their premise that estimation has moved away from being about size and is moving towards a greater focus on functional estimates. Our experience at DCG, seeing the widespread use of IFPUG function points, would underscore that premise.
Finally, the authors included a mini case study that helps to further advance the reader's understanding of the use of FSM. All in all, this article is a good read and provides some useful observations and information that anyone interested in sizing and estimating should know.
If you find yourself intereste in more information about COSMIC and Function Point Analysis, look no further, we have an article comparing the two.
Vice President, Software Performance Management
* Functional Size Estimation Technologies for Software Maintenance, IEEE Software, 11/2014