Built-in test and diagnostics: two different approaches

The built-in test and embedded diagnostics for two subsystems of the M1A2 main battle tank, the commander's independent thermal viewer and the hull/turret electronics unit, are examined. Each of these systems supports the requirements for elimination of special test equipment at the tank level and the use of standard army test equipment for test and repair at higher echelons of maintenance. The tradeoffs made during system requirements analysis and flow-down, which led to two unique design implementations, are described. The advantages and disadvantages of each approach are discussed