If you are using the computer BIOS field "Asset Tag" as a means to automate the Computer Asset entry for System Number you may be finding the CMDB Task "Inventory to Asset Synchronization is not updating the System Number with your Asset Tag. There is an article that is related to this issue, however it does not tell you a resolution for it. http://www.symantec.com/docs/TECH44306
The problem is with the task using a Inventory Data Class that does not contain a value for the CMDB Data Class to use for System Number. There is a Inventory Data Class in the Inv_HW_Chassis.[Asset Tag] that does have the BIOS Asset Tag value, but the task does not use it. You will need to open a case to get a new Stored Procedure as a workaround or wait for the fix in a future release.