Anyone have the experience of having to learn many things and pass many tests during training to keep the job?

I am having this experience with a state job with Arizona. What kind of job is it if you have that experience and what do you think of having to learn many information and pass the tests in order to keep the job?? Is it common with many jobs or not very common that you have to learn many things and pass many tests in order to keep the job?? Also, falling behind with the training can also cause you to be terminated. Do you think that's kind of strict or harsh that you can be terminated if you fall behind with the others in training ??