How to drive Quantity of an item in a BOM based on Options & Variants rules?

Hi,

With Options & Variants capability in windchill 9.1, how we can build the rules (Parameters, expressions, constraints, case tables, etc.,) to drive the quantity of an item under an Advanced Configurable Part?

Example:

Consider the below BOM:

Top_Part (Adv Config Part)
      Part1 (for option1)            Qty - 1
      Part2 (for option2)            Qty - 2
      Part3 (for both options)     Qty - 2 Meters for Option1 and 5 Meters for Option2

While configuring, selecting option1 should result in:

Top_Part
      Part1    Qty - 1
      Part3    Qty - 2 Meters

Selecting option2 should result in:

Top_Part
      Part2    Qty - 2
      Part3    Qty - 5 Meters

Can you please help in this?

Thanks,
Prabhakaran V.