How to get a list of custom WorkFlow used in last month

Hi Experts,

I have to perform a list of custom WorkFlow used in last month in my environment.

I run transaction SWIA but the ouput has the column "workflow" blank.

In any case, do you have some suggestion in order to get list of custom WorkFlow ?

Considering I found only one custom Business Object Type used in one only custom WF; is it possibile to create custom workflow without a custom business Object type?

Thanks a lot!

Best Regards,

Umberto