New hires on my service are watched for the first 6 months via a probationary status. During the 6 months, the new hires are watched by their fellow crew members and reports are written by the more senior crew members as to the new hires abilities. After 6 months, the new hire is either hired or let go.
Also, for each level a certain number of IV sticks, EKG rhythms, and other level specific tasks must be completed and signed off by their crew member.
This system appears to work pretty good, but there is a lack of ems professionals in the area, so my service sometimes has to hold onto some people that they normally wouldn't, so that they can cover shifts.