There are so many factors that go into Software Distribution. Any one of those numbers could be acceptable (70, 80 ,90).
I typically shoot for 95%+ over a week for a 200-500 node distribution.
Here are some factors to consider:
How many traveling people you have.
How many are on vacation.
How stale is you LANDesk database (how many have not checked in in the last 30 days)?
What type of distribution is it? (MS office 2010? A spreadsheet? A patch?)
Is the issue outside of LANDesk? (If you sat down in front of 20 machines and ran the install would any of them require further troubleshooting beyond launching the install)?
It also depends on if its a push or a policy.
There are several factors that wil effect software distribution. It ranges from the obvious to the hard to detect or troubleshoot.
Machine is off or not in the office.
Machine needs a reboot.
User cancelled the install.
Software is already installed or not required.
Basic network issues (cable is unpluged, etc)
Hard to detect:
Malfuntioning LANDesk agent.
Corrupt distribution point or package.
Firewall/VPN software malfunctioning or blocking installation.
Random network issue or improper configuration.
Setting up a test group from random users throughout the company will help resolve many of these.
I used to manage an environment with 4500~ machines and the averages went something like this. 60% first 2 days, 65-68% week 1, 70-80% week 2, 85% month 1, 90-95% month 3. After each major rollout, I always got the same questions. Why so long and how do we fix it? My answer was always the same: "Stop buying laptops, deny all vacation, force all users to work at the office between 8-5, shutdown their machines every night and no one gets admin rights..." You should have heard the laughter.......