PDCA (plan, do, check, act) is a well-known business loop for making improvements.
OODA (observe, orient, decide, act) is a well-known decision cycle used in military doctrine.
PDCA helps make organizations more efficient and effective.
OODA says the side that can execute OODA loops more quickly and accurately will one-up on their adversaries.
PDCA tends to have an inward focus.
OODA has an outward orientation.
PDCA is all about getting better at doing something.
OODA is about winning battles.
Like many things in life, simply doing one and not the other will not be sufficient in this fast-changing world.