The old aphorism - "Under-promise, over-deliver" - remains timely. But it's never been so relevant as it is now during an age when systems of all kinds are growing ever-more complex.

Witness a classic bad-PR event that has been on the front pages of London's newspapers and leading local TV newscasts. Heathrow Airport's new Terminal 5 opened with scores of canceled flights, enormous amounts of misdirected luggage, and a clear public understanding that while the facility may have opened for business, ...