Depending on the edition of Nintex Workflow you're using, absolutely.
If you're using Nintex Workflow Enterprise edition, there's a feature that allows you to see all in-progress workflows on your site.
If you're using Standard, however, things get a little more tricky. You can try running the following SQL script:
select I.WorkflowName, I.SiteID, I.WebID, I.ListID, I.ItemID, I.WorkflowInitiator, COUNT(P.WorkflowProgressID) as ActionCount
from WorkflowInstance I inner join WorkflowProgress P
on I.InstanceID = P.InstanceID
group by I.WorkflowName, I.SiteID, I.WebID, I.ListID, I.ItemID, I.WorkflowInitiator
order by COUNT(P.WorkflowProgressID) desc
However, both of these pale in comparison to what Nintex Analytics can offer you in terms of workflow metric insights. I would strongly suggest investigating Analytics if you're looking for real analytical insight into your environment.