A large part portion of the software industry skips this form of testing in favor of using a portion of production with health metrics to detect chaos. Which is alright, unless someone like Boeing does it with an airplane.<p>If unleashing chaos on users is bad enough for your business, then TLYF is a good pattern. Here are some scenarios that call for TLYF:<p>* Customer will die from chaos in software<p>* Customer will remove product if they experience any chaos<p>* Software is deployed somewhere that is hard to update - think non-internet connected devices, or regulatory required change control<p>* Chaos will cause significant loss of value<p>Both Boeing and Toyota failed to apply TLYF rigorously, resulting in uneccessary deaths.