This is part of the data entry form for a new MyBO. Some data is entered, a button is clicked, this process is run, and another field on the form is populated with the result of the search.
So I'm already part way through the process. The button click/lookup is also optional, so I can't assume that it will be required in advance.
The only reference I can find to initialisation is for rules attached to the BO. This is a process, albeit called from a rule attached to the BO.
My head is spinning a bit today ...