oclIsInState checks whether an object has 1 or more state machines defined - and if one of these state machines is currently in the state in question.

Article.allinstances->select(a|a.oclIsInState(#Manufacturing))

A state machine can be defined like this:

<a href="/File:2017-09-14_14h02_09.png" class="image" data-bs-title="File:2017-09-14_14h02_09.png" data-bs-filetimestamp="20170914120427"><img alt="2017-09-14 14h02 09.png" src="/images/thumb/2/22/2017-09-14_14h02_09.png/300px-2017-09-14_14h02_09.png" decoding="async" width="300" height="152" class="thumbimage" srcset="/images/thumb/2/22/2017-09-14_14h02_09.png/450px-2017-09-14_14h02_09.png 1.5x, /images/thumb/2/22/2017-09-14_14h02_09.png/600px-2017-09-14_14h02_09.png 2x" /></a>

<a href="/File:2017-09-14_14h02_09.png" class="internal" title="Enlarge"></a>

See also: <a href="/Documentation:State_value_as_a_string" title="Documentation:State value as a string" data-bs-title="Documentation:State_value_as_a_string">State value as a string</a>