What Is the Difference Between ACE and Lean?

I was looking at ACE on United Tech’s website and I have one question, “What is the difference between ACE and LEAN?”  Besides one has a C in it and the other has an L and an N in it…
I even did a quick web search and besides noticing a few concepts having different names but essentially the same desired result or goal, I didn’t notice any differences in these philosophies.  However, maybe there are some subtle differences that I missed.
Thanks…