You can build a Site Workflow, and schedule it to run every 15 minutes.
Then on your workflow use the action named "Query List" and query your list filtering the last 15 minutes.
Thank you for your help.
I forgot to say that I like to use a reusable site collection workflow. The workflow is based on a user defined site content type. Based on the site content type I like to create several document librarys. The workflow is added for every document library.
Is it possible to schedule the workflow to run every x minutes?
What are your starting options on your reusable workflow?
I like to start the workflow when an item has been added or created (event triggered). But it is also a good solution for me to use a time triggered workflow. Every X minute it has to look for new items.
in which case I would say that Fernando's suggestion to have a scheduled site workflow might work.