Improve Product, Not Process

Believing that process improvement will improve the product is like believing spending more time looking at the map before taking a trip will prevent you from running into a traffic jam along the way. Process improvement creates paint-by-numbers, it creates fast food. Which is fine if that's your goal, but don't expect anything other than paint-by-numbers or fast food. Otherwise, we're treading into Einstein's definition of insanity "Doing the same thing over and over and expecting different results."

If you feel you must improve your process, plan your process for change. There are too many uncontrollable variables to have any expectation of a successful delivery with a single waterfall method. So plan your process for more frequent changes, more frequent reviews, and more frequent releases. Hmm, this sounds like agile (without a capital A).