6 Essential Software Sizing Resources

Project managers and estimators have long struggled with the issue of how to measure software size. Really, before you can calculate cost and schedule, you will need some notion of how big the project will be. There are myriad of ways to size a project depending on the methodology you use and where you are in the planning process. Here at QSM, it's one of the common questions we receive, so we've devoted many years of research to the topic. Our website features a wealth of resources on sizing and in this post, we will highlight a few of the most valuable for anyone grappling with this issue or looking for a place to start.

General Sizing

• QSM's Software Sizing infographic is a great place to start. This easy to understand visual resource helps explain the most popular sizing methods and when to use them, the difference between functional and technical size, sizing challenges and more!
• Measuring Software Size - Insights from the Past to Guide the Future is another helpful guide if you're struggling with which sizing units to use. This PDU-approved webinar will help you determine what sizing measure will work for you based on your own historical data. This presentation is worth a watch no matter what development methodology you use and can help improve future estimates and in-flight project forecasts.

Function Points

• For those using Function Points as a sizing measure, QSM's Function Point Language Table is a valuable reference to save to your bookmarks. It contains updated function point language gearing factors for 37 distinct programming languages/technologies. Based on data drawn from 2192 recently completed function point projects from the QSM database, this table is regularly updated and users can request gearing factors for languages not found in the table.
• If you're having doubts about function points' relevance as a modern sizing measure, check out Function Point Sampling Holds Promise for Software Metrics. Originally published in IFPUG MetricsViews, Carol Dekkers and Joe Madden suggest a new way to repurpose function points to achieve estimating successes today.

Agile Sizing

• For agile development groups struggling with early sizing, QSM client Aaron Jeutter presents Rockwell Automation's technique of "Big Rock Sizing" in his article Big Rock Estimation: Using Agile Techniques to Provide a Rough Software Schedule / Resource Estimate. This approach is based on high level requirements that will be refined using agile techniques as the work progresses. Aaron further discusses this technique in his presentation for the QSM Virtual Conference here.
• Another article in QSM's Agile Round Table series, Sizing Agile Projects Consistently discusses how to determine size in a consistent enough manner across multiple products, projects, and agile teams so that you have good historical data on which to base an estimate.

This is just a small selection of the many sizing resources available to the public on our website. We encourage you to explore more of our sizing articles, webinars, and blog posts. QSM also offers sizing workshops and consulting offerings from industry experts. Contact us to learn more!