cannot specify interaction requirements where the system shall initiate
an interaction between the system and an external actor
can neither model a rich system context beyond its immediate environment,
including interaction between actors
impossible to express structures between use cases or a structural hierarchy
of use cases in an easy and straightforward way
provides no adequate means for dealing with use case interaction
There has been much research on analyzing the nature of these deficiencies and trying
to overcome them. It turns out that some problems can be fixed, while others are rooted
in fundamental concepts of UML and thus stay there.
