Meaning of "Premature Operation" for Failure Abstraction?

Hi,

I’ve read RAC’s FMECA document. link is: http://www.dtic.mil/dtic/tr/fulltext/u2/a278508.pdf

on page 41, there is an useful failure abstraction. In my FMECAs I’d like to utilize this abstraction however I am not a native English speaker so I couldn’t understand the true meaning of “Premature Failure”?

For the abstraction to be correct, the elements of the abstraction MUST not intersect and all the elements MUST span the whole world of failures.

So can you explain true meaning of “Premature Failure” and give an example which can not be explain by the other elements?

Whole set given in document is given below so you don’t need to download the document

A) Premature operation
B) Failure to operate at the proper time
C) Intermittent operation
D) Failure to stop operating at the proper time
E) Loss of output
F) Degraded output or reduced operational capability

regards