Change Scheduling Parameters in Order Header

Dear Experts,

I have correctly maintain the business requirement in OPU7.

But for special set of orders, I want to change the Scheduling Parameters in Order Header.

Eg:  "Do not adjust basic dates, dep.reqmts to order start"

But in my system "Adjust dates" field is not editable in the order header.

how can I activate this field?

I want get the Component requirement date into order start ( Only for this order )

Thanks in Advance

Ashok M