BOM-Usage probablity - Message no. CO607-Process order

Dear Gurus,

pl see the msg below.

Total usage probability = 120 for alternative group AA

Message no. CO607

This is a information message. I would like to change it as Error

In the O04C system messages i couldnt find this message. So i created a new mssage by making it as Error mssage.

But while changing the usage probability which goes beyond 100 system gives only information mssage only.

pl guide me