English to Czech Tech/Engineering Engineering: Industrial Process engineering

Dear colleagues,

I am strugling with the term "runoff" in the following context:
"Vendor agrees to tryouts and runoffs".
"Balance will be paid upon final runoff at buyer’s facility and complete fulfillment of the all responsibilities for this Order."
"Invoices (subject to applicable withholding taxes, if any) shall be paid 90% upon successful completion of run-off on Supplier’s floor".

I suppose "runoff" must be an inspection or testing procedure related to the testing of machines. (perhaps trial run?)
The context fragments are taken from a Request for Quote document regarding the delivery of a Leak Test Machine.

I'll be grateful for any hints or ideas...
Thanks in advance.

Regards,
Filip Zajicek