It all depends on you. I had one client who had a program to improve the cover on the metal chip dumpsters to prevent rain water runoff. Once that was completed to their satisfaction, they closed it and created a program for another aspect that was not as critical.
In your case, you have several choices. You could see if you can reduce it even more (continual improvement). You might also want to go into monitoring mode to ensure it stays down. Or you might want to look at alternative to get rid of the aspect altogether.
My doc says I have to lose weight. Once I get to my target weight. What do I do? I can try to lose even more, or I could monitor to make sure I don't gain any back, or I could monitor and also find some other health related goal. The important thing is to improve.