Software Development “Leakage”

Over the years, I’ve come to know software metrics expert, Capers Jones, Scientist Emeritus at Software Productivity Research (, as an esteemed colleague and friend.

Last week, Capers and I exchanged emails where he illuminated the effects of what he terms “leakage” as it relates to inconsistencies in recording and reporting project work effort.  Since I posted on this topic a week ago, I asked Capers for permission to post excerpts from his emails with you (he said yes):

Capers Jones:  “My original intent in 1983 was to identify and record every factor that influenced software by as much as 1%.  Leakage has as much as a 50% impact.  One of the reasons I go on site to collect data is because of leakage from software accounting systems.  Most accounting systems omit > 50% of the actual effort that goes into software projects.  The most common omissions are unpaid overtime, project  management, and the work of part-time specialists that support several projects such as quality assurance and technical writers.

Attached is a spreadsheet that shows the most common forms of leakage. (Dekkers’ note:  for anyone who would like a copy, please comment and include your email at the bottom of this post).

The main impact of leakage is that software project benchmarks based only on accounting data look to be at least twice as productive as they really are.  Any project with results > 15 function points per month probably have uncorrected leakage.”

These are many of the same issues I identified in my post last week about project hours.

What have YOU encountered on your projects?  Is leakage a problem in your metrics programs (or do you even know)?  Let me know what you think!

To your successful projects!


Carol Dekkers

Carol Dekkers provides realistic, honest, and transparent approaches to software measurement, software estimating, process improvement and scope management.  Call her office (727 393 6048) or email her ( for a free initial consultation on how to get started to solve your IT project management and development issues.

For more information on northernSCOPE(TM) visit (in English pages) and for upcoming training in Tampa, Florida  — April 26-30, 2010, visit

=======Copyright 2010, Carol Dekkers ALL RIGHTS RESERVED =======


5 responses to “Software Development “Leakage”

  1. Hey, you have a great blog here! Thank you for your info.


  2. Hi Carol,

    I would like to see the spreadsheet on the common leakage points



  3. Hi Carol,

    I have just recently come across the opposite. Small project, long duration, effort contaminated by folks booking a bit of effort to it.

    Bottom line, there are two numbers. What the effort accounting system states or might state and how much effort is really needed to develop and reasonably test the functionality.

    If you want the latter then you’ll have to do some digging.

    Regards Peter


  4. Peter,

    Good point about small projects and long duration. It also illustrates the need for “accurate” time reporting (and the basis of such) WHENEVER estimates of future projects is to be made from such past completed projects. Thanks for your comment!



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