Root cause analysis, using methods from Kaoru Ishikawa and Sakichi Toyoda, digs past surface symptoms to find the one process failure behind multiple problems. One hospital traced 17 failure points back to a single process gap.
The 5 whys technique, developed by Taiichi Ohno at Toyota, asks why repeatedly until you reach the true source of a problem. Roughly 87% of issues resurface within 90 days because teams fix symptoms, not the broken system underneath. Most root causes turn out to be embarrassingly simple
The fishbone diagram, pioneered by Kaoru Ishikawa, traces problems to their root causes using a visual cause-and-effect skeleton. Learn the six categories, frameworks, and how to build one.