Recently, I was working with a customer while he was adding a member to an iPart. He continually jumped between sketches and feature and the iPart table. We was checking the names and values of dimensions, then going to the table and changing the value for the new member. After doing that a few times, he asked me, "Is there any way I can change the values in the model without having to go to the table?"
To which I replied that there was. I pointed him to the Factory Scope/Member Scope setting. For users that are not familiar with the purpose of this setting, it allows a user to specify if a change is for the entire factory(all members) or for a specific member. By default Inventor is set to Factory Scope, that means as the user changes the model, those changes are applied to all members. If the user changes that setting to Member Scope, the edits that the user performs are applied only to the active member of the iPart family.
Member Scope works great for editing the parameters already on the table, but also can be helpful when controlling feature suppression. You are allowing Inventor to control and edit the table for you as you make changes. It is really interesting to see the impact on the table as features are added while in Member Scope. All the user has to do is add the necessary feature(s) and Inventor will handle adding the parameters and feature controls to the table.
Here is a Screencast that demonstrates the Power of Member Scope: