A troubleshooting session always starts with symptom or an error message or some kind of fault report.
This can of course be helpful in determining where to start.
If we did not have this sort of information but only new that there was a problem, we would have to test the entire system to find the fault. iTech would then recommend tests based on probability and all the other techniques until it finds something wrong and then home in on that.
However, if we have some indication such as:
I have a hoist problem, or
The oil warning light is on, or
an error message appears on the screen.
then it can help us identify an output or test point that has failed. This can reduce our MTTD by giving us an indication of where we should start testing. E.g. if I have a hoist problem, I wont start by testing the air conditioning in the operator's cabin.
It may also give us some a prior information that tells us about other parts in the system. E.g. the oil warning light is on tells us that the power supply must be working (or the light would not come on) so we can assume their is power in the system.
Just as this information is helpful to an engineer when he is troubleshooting, so also can it be helpful to iTech. This information is input via the Rule library. Rules are not required for troubleshooting, but can help optimize our MTTD.
