Brother mfc8440 - Mtbf; Mttr

CHAPTER 5 PERIODIC MAINTENANCE
5-26
4. MTBF / MTTR
The meantime between failure (MTBF) and the meantime to repair (MTTR) for this machine
are as follows;
MTBF: Up to 4,000 hours
MTTR: Average 30 minutes except the periodical maintenance parts (the Paper Feeding Kit)
and the machine control boards whose MTTR is average 10 minutes.