One by one over the years Apple has eliminated the need for manual "housekeeping" (or should that be "computer keeping") chores we used to perform out of habit. If you are running OS X 10.6 or later, there is no reason to manually run the maintenance scripts. If your Mac is turned off at the times a maintenance script would normally run (10:30 PM and 5:30 AM) they will run in the background when the computer is booted up the next time.
Some of those regular chores we used to perform religiously, such as defragmenting files and volumes can even be counter-productive (especially on fusion and SSD drives). IMHO if you are running Mavericks or Yosemite,
if it aint broke — don't fix it is the best maintenance policy. I still have maintenance tools like
TechTool Pro 8 and
Drive Genius 4 around
just in case but truth be told just about the only time they are ever launched is when I get an update to the app. The only
maintenance apps I run with any degree of regularity are
CleanApp when I am getting rid of old seldom or never used applications, and
MacPilot if I just have to diddle with otherwise hidden preference settings and even those are used less and less often.