Active manufacturing assemblies are assemblies that have been designated for use during a specific Process Plan Browser session. A process plan can have multiple assemblies associated with it, and therefore numerous related parts. Designating an assembly or assemblies as active, ensures that only the related parts in those assemblies can be used for part allocation during that session of the Process Plan Browser. This reduces the number of related parts that are displayed during that Process Plan Browser session making it easier to find and allocate the necessary parts.