Pete,
I am a new hire/ apprentice where I am at, and there are many certifications I have to pass in a timely basis in order to be able to perform my job duties that are expected of me. Here's how it's handled.
I am hired on a contigent basis, temporary.... the first 4 weeks was through a temp agency, and there were goals they wanted me to meet during that time. I just met them. So they renewed it, for another period of time through them, but still on a contingency for another period of time, as temporary still (but with benefits beginning). During this period I will have to pass certain certifications, and be able to then do production work with reliable ammounts of passable product. If you do not make it, they do not renew your contract when it comes due. You also get $$ each time you get renewed. It's awfully motivating. :)
I am the type that would be motivated anyway, but this system sure gives them a way to weed out the ones who aren't like me. If you know it means you could no longer have a job soon.... you might go ahead and try to pass that test. AMPLE training and knowledge is provided to make sure you are able to do so.
FWIW
Jenn