My professional career as a multidisciplinary engineer has been in the realm of assuring reliability of safety-critical products, sub-systems and components as well as in working in the business-critical areas of eliminating waste and making organizations LEAN.
The quality discipline can seem to get complicated, particularly in complex systems, but the reality is that it is almost tediously simple: never stop applying good old habits, use the tools, keep the edge sharp ... relentlessly use the Plan-Do-Check-Act cycle over and over and over ... optimize systems in a quantified form by seeking first to understand with the Define-Measure-Analyze-Improve-Control framework ... break down systems and exhaustive prioritize risks with Failure Modes Effects Analysis and aggressively applying the Pareto principle ... less than 1% of the issues cause well over 99% of the damage.
LEAN is hardly any different than the realm of Quality. It's almost too dreadfully simple ... people want to complicate it, but it is necessary to RUTHLESSLY use the DOWNTIME mnemonic to see and eliminate waste ... if you want to make something LEAN, you must never ever forget D.O.W.N.T.I.M.E. ... get rid of Defects, Overprocessing, Waiting, Neglect, Transport, Inventory, Motion, Ego.