software solutions / project leadership / agile coaching and training

The relative cost of fixing defects

Posted on November 20, 2008

I saw a very interesting chart today…

The Relative Cost of Fixing DefectsSource:

If this doesn’t convince you of the value of unit tests, I don’t know what will. The cost to fix bugs in production could be dramatically higher than the cost to fix them in development, which is why having a suite of unit tests that you can run when you make changes is invaluable because it will prevent you from getting into these costly scenarios where you have to fix nasty bugs in production.


  1. “If this doesn’t convince you of the value of unit tests, I don’t know what will.”
    Absolutely. I am a sucker for nice 3D bar graphs, and basically believe anything they tell me.
    Also….brown eyes. I never could resist them.

    blindman — November 21, 2008 @ 10:45 am

  2. Nice post. I wish I didn’t feel like I was signing a contract every time I made estimates. Regardless if the client says, ‘it’s just an estimate’ or not, as soon as you mention a number with the word hour(s), there is an expectation is still built.

    Ben Wagaman — December 13, 2008 @ 8:23 pm

  3. [...] TDD Design Starter Kit: It’s All about Assigning Responsibilities TDD Design Starter Kit – State vs. Interaction Testing TDD Design Starter Kit – Dependency Inversion Principle TDD Design Starter Kit – Responsibilities, Cohesion, and Coupling TDD Design Starter Kit – Static Methods and Singletons May Be Harmful Succeed with TDD by designing with TDD Unit Testing Business Logic without Tripping Over the Database Haacked on TDD and Jeremy’s First Rule of TDD Jeremy’s Second Law of TDD: Push, Don’t Pull Achieve Better Results by following Jeremy’s Third Law of TDD: Test Small Before Testing Big How much design before unit testing, and how much design knowledge before TDD? So How do You Introduce TDD into an Organization or Team? Pair Programming Bot Why write unit tests? Empirical Studies Show Test Driven Development Improves Quality The Relative Cost of Fixing Defects [...]

    TDD Starter Kit - Sample Projects and Links « Jon Kruger’s Blog — October 12, 2012 @ 9:17 pm

  4. [...] just bugs. Security issues may have more severe consequences than regular bugs, but most regular bugs are expensive to fix once the software is deployed as [...]

    Building Both Security and Quality In « Secure Software Development — October 29, 2012 @ 8:05 am

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I have over 15 years of software development experience on several different platforms (.NET, Ruby, JavaScript, SQL Server, and more). I recognize that software is expensive, so I'm always trying to find ways to speed up the software development process, but at the same time remembering that high quality is essential to building software that stands the test of time.
I have experience leading and architecting large Agile software projects and coordinating all aspects of a project's lifecycle. Whether you're looking for technical expertise or someone to lead all aspects of an Agile project, I have proven experience from multiple projects in different environments that can help make your project a success.
Every team and every situation is different, and I believe that processes and tools should be applied with common sense. I've spent the last 10+ years working on projects using Agile and Lean concepts in many different environments, both in leadership roles and as a practitioner doing the work. I can help you develop a process that works best in your organization, not just apply a prescriptive process.
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