Process Model

No we can not add PV in editing mode.

You can change the configuration on nodes in the active instance but do not add the pv, in the Properties tab this will disappear when you edit the active instance.

You **can** add a PV in an instance - the counterintuitive thing is, you have to add it in monitoring first (in the Properties / Variables tab), then when you switch to Editing, you can use it there.

For some weird reason, they never provided the ability to add a new PV in an instance directly within Editing mode - though when necessary you can do it by the slightly more clumsy method I described above.

As an aside - when posts are given a subject line like "Process Model", it's very unhelpful - other users here have no clue what your question might really be about when browsing the list of topics, and then of course over time we accumulate dozens (or perhaps even hundreds) of posts all with titles like "Process Model", "Expression Rule", "Error", etc etc. 

Generally I'd suggest that the post's subject line should either be a very brief version of the question (i.e. "Can I add a new PV in an active instance?"), or otherwise, at least give a sligthly-less-vague idea what the post will be about in just a phrase or short sentence.