We are using Pega Salesautomation 7.13 and are adding a new work type "Order" which should be accessible from the navigation on the left:

I use the Create new work action for the new navigation item which works fine:

The only problem is that I don't know how to close work objects if a new one is opened.

Let's say you click on the Order item in the navigation rule then a new Order case starts. I process this case to the first or second assignment and click on Order in the navigation again - another Order case starts, but the first Order case and this thread is still opened.

I tried analyzing another application that uses a portal with tabs and executes the Work-.DoClose activity. If I launch this activity as an event (for a second navigation item for testing) nothing happens when I click on it.

The problem is that every Order case loads huge Data pages which will eventually slow down the requestor when five or ten Order cases / threads are opened simultaneously. The business requirement is to close the previously opened thread if a new case is started. How can I implement this?