which is the higher serial number on an appliance 9BP00Q2 or H0PQY03

Might be an obvious question but what serial number is higher 9BP00Q2 or H0PQY03.

Just learned that when all things equal the serial number plays a role in Active/Standby.

Explanation of why one serial number is higher the the other would be helpful...Im guessing the Alpha (H0PQY03) is higher then numeric?

Thanks in advance