During RAMS this year, Wayne Nelson made the point that language matters. One specific example was the substitution of ‘convincing’ for ‘statistically significant’ in an effort to clearly convey the ability of a test result to sway the reader. As in, ‘the test data clearly demonstrates…’
As reliability professionals let’s say what we mean in a clear and unambiguous manner.
As you may suspect, this topic is related to MTBF. Simply saying ‘reliability’ instead of ‘MTBF’ would convey what we really mean. If the message requires specific values, instead of ’50,000 hour MTBF’, say ’98% reliable over two years’. And, if you absolutely have to use MTBF, always add the duration over which the failure rate (1/MTBF) is relevant.
During a panel at RAMS a few few panelist spoke of the state of various reliability related international standards and mentioned the continued use of MTBF. When challenged, which I’ve been known to do on the topic, they defended the continued use of MTBF due to it’s widespread use. They also acknowledged that the common misunderstanding and misuse of MTBF, and agreed that using ‘reliability’ is more meaningful. Yet, they contended that the overall widespread use of MTBF warranted the continued use in the standard’s language.
It is my contention that the standard’s establish and reinforce the language that we as a profession use. We should expect that any standards’ language is clear and easy to understand. While MTBF, in itself is a perfectly meaningful expression, when used correctly, it does not currently communicate the intended message. Changing the term ‘MTBF’ to ‘Reliability’ in standards would encourage our profession and those that rely on reliability standards to elevate the discussion; to speak and write clearly; and, to avoid the communication errors surrounding MTBF.
The acknowledged widespread misunderstanding is further propagated by the repeated appearance in standards. Let’s change that.
One of the objections voiced is the ‘we’ve always done it that way’ type argument. This is related to the early medical profession’s use of Latin, as a means to cloak the professional in an aura of professionalism (educated elite members reinforced with arcane language). A major objective of the reliability profession is to enable the design and management teams to make good decisions while considering the full reliability impact. Using ‘arcane’ or difficult to understand language does not serve our profession nor provide a service to the design and management teams.
We already facing the daunting task of clearly explaining the range of statistical tools we routinely use to solve problems. Adding the term ‘convincing’ will help in that area. Let’s continue to improve our collective language by avoiding the use of MTBF also.