Definition of poka-yoke (as given in Wikipedia) is, any mechanism in a lean manufacturing process that helps an equipment operator avoid (yokeru) mistakes (poka). Its purpose is to eliminate product defects by preventing, correcting, or drawing attention to human errors as they occur.
Googling around on the benefits of Poka Yoke would throws up tons of results with astonishing numbers. People have reported nearly 98% increase in accuracy in their system , 0% error, 98% cost savings etc.
A very good introduction about Poka Yoke is available here.
The popular methods in Mistake proofing include:
1. Contact Method
2. Fixed Value Method
3. Motion Step Method
You can get more details about each of the above methods here.
At the end of the day Poka Yoke is all about finding ways to stop mistakes or identify the mistakes before they occur. Even though it was initially invented for the manufacturing industry, it is being applied to other industries like software too.
Some thoughts about applying Poka Yoke in Software development can be found here and here. Automated software testing practices applied on Unit, Component and Integration testings are classic examples of Poka Yoke in software development.
Recently I came across this website where the author has offered some tips about applying Poka Yoke for mistake proofing marketing. One can also download free presentation about the concept on the same website.
This website is dedicated about Poka Yoke with wealth of materials about this concepts, certifications, etc.