The serial number can be collected easily using BigFix. However, warranty information (such as the warranty start and end dates) is not maintained by BigFix itself. This information resides with the device OEM (Dell, HP, Lenovo, etc.) and must be retrieved from the respective OEM's warranty service or API.
A possible approach would be:
Use BigFix to collect and export device serial numbers.
Store the serial numbers somewhere locally.
Develop a script or service that processes each serial number, identifies the device manufacturer, and queries the appropriate OEM warranty API (or other supported warranty lookup service).
Retrieve the warranty start and end dates from the OEM.
Write the results back into BigFix using client settings or an external data import process, allowing the information to be exposed through Analysis properties for reporting.
In short, BigFix can provide the device serial number, but retrieving warranty details requires integration with the OEM's warranty service, as this capability is outside the scope of BigFix itself.