Fail FAST is a philosophy that suggests if a proof-of-concept effort isn’t successful, we can try a different approach and if none of the approaches are successful, we cut the losses.

The principle behind it is that rather than continuing on a project that would have eventually failed, the remaining funds and resources from the project can now be directed to other projects that are AWAITING resources.

Fail Fast principle is also applied at the software bug lifecycle. As we know, the longer it takes for a bug to appear on the surface, the longer it takes to fix and the greater it costs.

Fail-fast makes bugs and failures appear sooner, thus:

• Bugs are earlier to detect, EASIER to REPRODUCE and faster to fix.  
• It’s faster to stabilize software.
• Fewer bugs and defects will go into production, thus LEADING to higher-quality and more production-ready software.
• The cost of failures and bugs are reduced.

Fail-fast is the principle behind many agile practices like Test Driven Development and Continuous Integration.