Manufacturers, particularly in the auto and aerospace industries, have been improving efficiency for many years. And while a sick child isn’t a Camry, Seattle Children’s Hospital has found that checklists, standardization and nonstop brainstorming with front-line staff and customers can pay off. The program, called “continuous performance improvement,” or C.P.I., examines every aspect of patients’ stays at the hospital, from the time they arrive in the parking lot until they are discharged, to see what could work better for them and their families.