An effective electronic maintenance training program is dependent on the ability to insert faults into training equipment so that students may have hands-on experience in troubleshooting "failed hardware". The faults, and method of presentation to the student, must reinforce the training objectives while at the same time demonstrate the classic failure mode of the training equipment. Ideally, the method of fault insertion will be: transparent to the student, low cost, easily maintained, require a minimum of support documentation, be remotely and rapidly controllable, limit wear and tear on training equipment, and pose no safety hazard to personnel or equipment.

The increased complexity and size of operational systems coupled with higher costs for personnel and training dictate the need for a more realistic, effective, and efficient fault insertion technique as opposed to those in common use today. This paper will examine the concept of a microprocessor based fault insertion device (FID); a technique which has been successfully utilized in several major training systems. Comparisons will be made between a FID and other common methods of fault insertion.