The Inventory to Asset Sync Task copies Manufactuer, Model, Serial Number into differnet tables. It is typically run on a nightly schedulue.
You can see these three bits of information show when you right click and choose Edit for each computer object...scroll to the bottom and you will (should) see it poplulated. If it is not it usually means that there is a problem witht that asset e.g. It is not reporting Inventory because the Inventory plugin is not installed.
It is important to have this information correct for two main reasons:
1. It shows Healthy vs unhealthy assets
I create a monster report that has dozens of fields and is exported each day at 6am. In this monstor report I show those three columns so that I can easily see which ones do not have that information, and react accordingly (hunting down broken agents).
I'd say this is your 'root cause' of it not being populated so check out the assets not reporting. Remember this sequence 1. Agent Installed 2. Inventory Plugin deployed 3. Inventory Collected, 4. Overnight 'Inv to Asset Sync' updates tables (depending on how you schedule this might take a week)
2. It keeps this information after the asset has been purged by the 'Inventory Cleanup task'.
We want to keep a record of all our disposed assets and because of this we don't ever fully delete any computer objects. Because Altiris wipes everything through the Inventory Cleanup task', the only way to know Manufactuer, Model, Serial Number, is to have it added in here!
This is one of the krappy ways this product works, more thought should be given to asset artifacts adn this topic, but because it's to hard to change how it works, we just adapt to it's krappy behaviour
Another important thing to note is that if you don't have agent installed on the endpoint, then you need to do this manually. Get yourself a resource to enter this information if it's feasable, or else you can go through the whole cmdb import process as another option