Hello Julius,
Thanks for your wonderful explanation.
I am not a developer, so I need to take the help of a Developer in this.
They have came up with the requirement for restricting in MM* T-codes alone.
Currently we are on Release 740/ 06.
Though the design goes to a developer, I am thinking on how they will be able to make this out, As already there may 1000's of User who might be using this field for Material Master Maintenance..
If we need to restrict the access, the logic would be to develop a new custom object and User who having access for this object will be only able to edit and rest will see this see this field as In-active/ Greyed out.
Since our client authorization concept is more into User Specific authorizations, there is a huge chance for multiple users to report this as an error once the code is released.
Do we have any other option other than this?? Is this the right approach?
The requirement is under discussion with different stakeholders. That is the reason, I just put this up here 
.
Regards,
Jacob