German to English Social Sciences Psychology

The XX company produces and markets psychological tests. Normally customers (other companies) buy the tests and use them themselves for things like personnel selection, but if the customer prefers then XX can carry out the testing for them - that's Auftragstestungen (i.e. they are commissioned by the client to do it). I don't like "testing to order" or "contract testing" or "testing commissions" - are there any better expressions?