What happens when a product lasts too long? How long is good enough? Every product is different, and our ability to define what’s “long enough” is fraught with uncertainty. If it wears out prematurely, your customers will go elsewhere. If it lasts too long, they won’t need to come back.

In “The One Hoss Shay,” a poem by Oliver Wendall Holmes, a deacon is confounded by the various parts of his carriage that fail, and he decides to do something about it:
“But the Deacon swore (as Deacons do,
With an ‘I dew vum,’ or an ‘I tell yeou,’)
He would build one shay to beat the taown
’n’ the keounty ’n’ all the kentry raoun’;
It should be so built that it couldn’ break daown:
‘Fer,’ said the Deacon, ‘t’s mighty plain
Thut the weakes’ place mus’ stan’ the strain;
’n’ the way t’ fix it, uz I maintain,
Is only jest
T’ make that place uz strong uz the rest.’”

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