Windchill access control doesn't take views into consideration. With active usage of MPMLink, the use cases around involving manufacturing, plant and service folks into the PLM are increasing.
If Windchill adds view base access control it will solve many issues. For example, a plant1 user should not be able to see plant2 BOM. All plant users should not see engineering BOM. Currently with common access they see all of the views (though it can be controlled with filter, but in general), causing confusions.