The Serial Number barcode is defined as follows:

First 5 digits = Part Number
6th and 7th digits = Year (08 = 2008)
8th and 9th digits = Week (45 = 45th week of that year)
10th = Internal Control Code
11th – 15th digits = Serial Number

OR

First 5 digits = Part Number

6th digit = Internal Control Code 7th and 8th digits = Year (08 = 2008)
9th and 10th digits = Week (45 = 45th week of that year)
11th – 15th digits = Serial Number

* For ODM/OEM products, Serial number rule may be different.