Hi Sudip
In the Standard system thats not possible.
You define a Production Version with the desired routing and that becomes the basis of Costing.
If you have multiple Production Versions, the first valid production version becomes the basis of Costing
However, if you have significant difference between the cost of each routing, then you can use Mixed Costing wherein you will maintain Procurement Alternative in CK91N, Mix ratios in CK94 before you do CK11N
In this case, each Production Version is costed individually and then weighted average Std cost is calculated based on the Ratio you maintain in CK94
Std Cost Based on Routing 1 - 100 USD
Std Cost Based on Routing 2 - 150 USD
Mix ratio maintained in CK94: 50:50
Final Std cost release would be 125 USD
Based on this understanding, you can choose the further path. But you cant apply the Routing that would result in Lowest Cost.
Ajay M