Hi Sandeep,
Let's first understand the concept.
Suppose an Equipment started operations and worked for 1 year. Suppose this equipment underwent Breakdown for 5 times in this period. like this
1st for 10 hrs
2nd for 3hrs
3rd for 8hrs
4th for 20hrs
5th for 17hrs
MTTR = (10 + 12 + 8 + 20 + 5) / 5 = 11Hrs
MTTR is nothing but the average Repair period.
Now what is MTBR?
Think about the intervals between these Breakdowns.
Interval between 1st and 2nd Breakdown - 80 days (1920 hrs.)
2nd and 3rd -- 30days (720 hrs)
3rd and 4th -- 180 days (4320 hrs)
4th and 5th -- 20 days (480 hrs)
MTBR = ( 1920 + 720 + 180 + 20 ) / 4 = 3720 hrs
Now let's come to you queries
1. Obviously MTTR for the 1st breakdown will be equal to the Downtime of the first breakdown.
MTBR not applicable because there is only one breakdown.
Even MTTR is nor applicable for this very reason.
2 & 3 I think these have been answered in detail.
For Calculations of MTBR, the Startup date in Equipment Master is taken as reference date. If this field is blank, then the Malfunction Start Date of your 1st Breakdown Notification will be taken as reference date.
4. For this you need to go for a simple development.
Jogeswara Rao K