The "Design" view should be the automatic default set in the create part wizard, so all you might need to do is go to the Type and Attribute Manager and for this particular object type (WTPart base type, assuming your question), you should be able to edit the type, go to Layouts, then select the "Create" layout and simply remove the "View" attribute by dragging it back over to the left-side window. This keeps the View attribute applied to the part, but removes it from the create layout. No OIR modification would be necessary here.
If you are trying to avoid the manufacturing view altogether, you may also want to make this change for other layouts, particularly the "Edit" layout.
If you are ever looking for more specific or in-depth help as you get more involved, feel free to send me an e-mail at robert.sindelar@eccellent.com. We have several years experience in all thing Windchill and are here to help!
