Product Maturity 1

8Run-In

8.1. Run-in principle

A particular type of burn-in is known as the run-in. This concept was well-known several decades ago, notably for automobiles. In the past, the purchase of a new car was accompanied by a run-in stage: longer or shorter, not too rapid, not too high in rpms, daily check-up of levels, etc.

Figure 8.1. Run-in of a car engine. For a color version of this figure, see www.iste.co.uk/bayle/maturity1.zip

First, let us recall what the run-in of a new car entailed. It covered a period of time between the purchase and the first few hundred kilometers traveled, say up to 1,000 km on the counter. The idea was to drive with almost excessive caution, allowing all of the parts and gears to properly interconnect and to erase all machining traces. Conversely, being impatient and pushing the gas pedal to the floor could generate even more friction between the parts, distorting them and increasing oil consumption and, consequently, the number of failures.

On the contrary, a failure is not always defined as the cessation of a function of a component, or its destruction. Indeed, it can also be about no longer reaching a certain level of performance. This is particularly the case with components that have a “reference” function, for example a voltage regulator (electrical voltage), an oscillator (frequency), etc.

These components generally provide a physical quantity ...