Poka-yoke is Japanese for “error-proofing”. A poka-yoke device is any type of device or process used to prevent errors or to immediately handle them.

There are two types of poka-yoke devices: detection devices and prevention devices. A detection device is used to detect when errors occur and immediately provide notification of the error. A prevention device is used to prevent an error from occuring in the first place. Prevention is preferable, but not alawys possible.

Implement poka-yoke devices to ensure high quality by finding ways to ensure mistakes are minimized, in software products and in business processes.

For example:

• Developers can use unit testing as a regular coding practice (“test-first” programming).
• Application designers can use peer reviews to ensure nothing was missed in the designs and to spot potential issues.
• Every iteration can undergo usability reviews from staff experts using the designs as a guide, and QA can leverage the designs to write test cases.
• Inline editing solutions can be used in forms so that users can’t submit data until a form is correctly completed.

An ounce of prevention is a pound of cure. The more you do up front to prevent mistakes – quickly, of course - the less money you’ll spend fixing things later, and the happier customers will be.

(This tip is from the Kaizen Software Manifesto. Learn more about it here.)

Posted by Robert on March 15th, 2007