What's Your Fault Feedback Ratio?

By Johanna Rothman

November 4, 2002 12:00 PM ET

Computerworld - Most of us track faults (also called defects, problems, issues, bugs) during the system test part of the project. However, many project managers don't track how many of our fixes are successful and how many fixes are bad -- either introducing a new defect or not completely fixing the original defect. If you're looking for better scheduling of your system test and project completion, start measuring your Fault Feedback Ratio, the FFR.
Here's how to calculate your fault feedback ratio:

Fault Feedback Ratio =	Fixes that require more work
	All the fixes

When I've measured successful projects, the FFR stays under 10% throughout the project, meaning that no more than one in 10 fixes are problematic as the work progresses. (Don't be deceived by a low FFR and a high overall fault count. With a large total count, the defects can be too overwhelming to successfully manage.) A low FFR and a not-too-high overall defect count also implies that the developers have a relatively easy time finding and fixing the problems. The testers don't have too much trouble keeping up with testing the fixes, because the fixes haven't broken other pieces of the software. The project team is progressing.
On the other hand, an FFR of 15% or higher means that people are spending significant time finding and fixing problems. A higher FFR and a low defect count may mean that the problematic fixes are in the same part of the code base. A higher FFR and normal or high defect counts, may mean the developers may have trouble detecting where to fix the problems, and the testers may have trouble verifying the fixes are good.
Once the FFR hits 20%, you're making dubious progress on the project because your team is spending too much time re-fixing problems they thought were already fixed and retesting those fixes.


	Johanna Rothman consults on managing high technology product development, focusing on project management, risk management and people management. Join the online discussion about this column.

On one project, the FFR started at 18% in the implementation phase, when the project team started to track their defects. Because the developers had completed the design before they started coding, they had trouble fixing the defects quickly. To make up the time, they took shortcuts for fixing the defects, and stopped doing peer reviews on the new code.
By the time the project was supposed to start system test, the FFR was up to 23%. The project had met its previous milestones, but the team was unable to predict the

Recommend Digg Twitter ShareThis

Email Print Send Feedback Reprints

Additional Resources

POLL RESULTS

Leading IT Pros Weigh In on Top IT Issues

Accelerate your knowledge of the IT world you inhabit by viewing the results of a series of polls taken by your IT peers. These polls of 100+ IT professionals each are available for full viewing. They cover key topics such as virtualization, processor performance, green IT, cloud computing and many others. Be a part of the buzz.

WHITE PAPER

For Best Results, Think Beyond the Box

Technology is complex. Keeping it running productively shouldn't be. To that end, you want to minimize the number of solutions needed in-house to simplify operations, maintenance, and support. Kodak offers a best-practices model. One company provides support for both scanner and software, for fast problem resolution without vendor finger-pointing. Download now!

WHITE PAPER

Accelerating the Path to Demand Intelligence with a Demand Signal Repository

Utilizing demand intelligence improves the precision of pricing, product assortments, channel/store placement, and promotion, which are all essential for sustainable revenue management performance. Learn more, download this free whitepaper today.

White Papers & Webcasts

The High Performance Workplace
In this paper we examine the challenges and define the critical steps CFOs, CIOs, COOs and CEOs, in midsized global companies, can take...

How to Reduce Eclipse BIRT Development Effort for Data Visualizations
Web applications can come with a long list of visualization requirements for structured data. By delivering your output through the BIRT Interactive Viewer,...

Extend, Replace, or Convert; which is the best way forward for COBOL Applications?
There are a number of choices when looking at ways to take existing COBOL applications forward. This white paper discusses the most common...

Usability Is Everything
Learn what sets Workday's HR and Payroll solutions apart from the competition....

Accelerate SSL Encrypted Applications
The amount of SSL traffic is growing in the enterprise. Because it is encrypted, it cannot be properly controlled and accelerated. Blue Coat...

The Value of Real SaaS at Workday
Cost savings, speed to value, and innovation brought to the enterprise by Workday's software-as-a-service solutions for HR and Payroll....

ESG Lab Field Audit
Many companies have successfully implemented Riverbed WAN optimization solutions within their Cisco networks. This ESG Lab Field Audit document explores the success that...

SaaS at Flextronics, Inc.
Dave Smoley, CIO of Flextronics, discusses the real value of software-as-a-service and why he chose Workday for his HR solution....

Shape Your Apps Strategy to Reflect New SaaS Licensing and Pricing Trends
Why are smart companies choosing software-as-a-service? Find out in the complimentary Forrester Research report...

Why Compliance Pays
This OnDemand webcast explores the relationship that firms with best compliance records have higher revenue, greater customer retention, lower financial losses from data...

All White Papers | All Webcasts