Tuesday, February 18, 2003

SCRUM: Review of Agile Software Development with SCRUM

Slashdot review of best available book on SCRUM

Schwaber, K. and Beedle, M. (forward by Jeff Sutherland) Agile Software Development with SCRUM. Prentice Hall, 2001.

This book holds a remarkable ranking of 602 on Amazon's best seller list and gets five star reviews. Timothy Lord adds a great review on Slashdot:

"Anyone and everyone on Slashdot probably knows that business-driven software development efforts all too often end up as a mess. After a number of years of observation, research, and fine tuning, Ken Schwaber and Mike Beedle have released a book that makes a subtle but vital revelation about the nature of software projects and how to better run them. Learning what Scrum is and how to practice it is not all that profound. However, sitting back and realizing why Scrum works and how it addresses the fundamental flaws of the last 20 years of software engineering is. This book could be viewed as the "why" component to all of Extreme Programming's "how."

Click here for more.

Thursday, February 06, 2003

SCRUM: Keep Team Size Under 7!


Today, I wrote up an experience report on using SCRUM in large development teams for a new book that Craig Larman is writing. I described how a few teams in a 500 person development group generated production code at five times the industry average, while most of the teams who executed SCRUM well, only doubled productivity over industry average. One of the problems in the large organization is that it was culturally prone to a team size of about 15 people and there was a lot of internal resistance to reducing team size. I now think that this may be the primary reason only a few teams moved into hyperproductive mode. The hyperproductive teams would always split into subgroups of 7 or less, while the poorer performing teams insisted on working as a group of 15.

Jones, Capers. Applied Software Measurement, Second Edition. McGraw Hill, 1996.

There is plenty of data to show that team sizes over 7 result in significantly lower productivity. Any team over 7 in size should be split up into multiple SCRUMs.

Rubin, Howard (Ed.) A Metrics View of Software Engineering Performance Across Industries. IT Metrics Strategies V:9:3, September 1999.

Average cost per function point across over 1000 projects in Rubin's Worldwide Benchmark database is $2970. For teams of size 7, the average cost was $566 per function point. Most companies productivity is (by definition) the industry average in function point analyses done by Software Productivity Research. We may spend about 6 times the necessary cost for each project we do on the average.