In the ISA95 spec Physical Assets do not have multiple inheritance and therefor map simply to UA types. The companion spec introduces multiple inheritance by defining class and type and splitting attributes between them. Since the attributes are split this adds needless complexity to an implementation. The decision to do this may have been influenced by B2MML models but there should be a clean mapping of ISA95 to UA, no matter what B2MML is doing. The solution proposed for Equipment does not eliminate the complexity. The spec should be fixed to implement a simple implementation and B2MML implementations can extend the simple version.