For want of a nail, the shoe was lost.
For want of a shoe, the horse was lost.
For want of a horse, the rider was lost.
For want of a rider, the battle was lost.
For want of a battle, the kingdom was lost,
And all for the want of a horseshoe nail…

This old proverb—which can be traced back to the 1390s—has been used countless times in a variety of ways over the centuries. Benjamin Franklin, for example, included a version of it, preceded by the words, "A little neglect may breed great mischief," in Poor Richard's Almanack in 1758. (That's when the American colonies were tangling with the English Parliament.) Many years later, during World War II, the verse was framed and hung on the wall of the Anglo-American Supply Headquarters in London to remind everyone of the importance of seemingly trivial repair parts and inventory replenishment. I'm borrowing it here to make the same point to today's capacity assurers: We're only as strong as our weakest link.

Case in point
It is highly unlikely that anybody, upon seeing an unshod horse, ever thought a kingdom would actually fall because of a missing nail. In the heat of the battle, hardly anyone would have time to notice the work of the lowly blacksmith. Few would truly appreciate the value of a properly fitted horseshoe affixed with nails when the horse is in full gallop—except the smithy himself. When catastrophe strikes, however, 20/20 hindsight really brings the nail into a much sharper focus, and the smithy gets the blame. There are real-life historical examples of the truth behind this proverb.

Consider this: On the bloodiest

day in American history—September 17, 1862—the Civil War Battle of Sharpsburg (also known as Antietam) resulted in nearly 23,000 casualties. After crossing the Potomac River into Maryland on September 9, 1862, Confederate General Robert E. Lee divided the 45,000-man Army of Northern Virginia and spelled out the location for each group on written dispatches (Special Order No. 191) sent to various commanders. All but one of these dispatches were delivered by couriers on horseback to the commanders. The one that didn't make it accidentally dropped from the courier's pocket when he he stopped along the way to relieve himself. Unfortunately...(Read whole article)