It's astonishing how even the biggest companies can make such elementary mistakes.

And the blunders featured in Business Nightmares with Evan Davis (8pm, BBC2, 9 May) may have been golden oldies, but they still resonate down the years.

First up was Unilever, which, as many will recall, was so envious of the growing popularity of rival P&G's Ariel that in 1994, at the height of the soap wars, it launched Persil Power. With its cleaning "accelerator", it sounded just the ticket to take on the more "scientific" Ariel. Unfortunately, in its haste, Unilever had neglected to do something rather important - test the product properly.

If you needed to dispose of a body, this stuff would probably do the trick - and P&G knew it, issuing a press release declaring, in delightfully pompous language, that with repeat use clothes "became shredded to the point of indecency".

As former Lever Brothers MD Andrew Seth admitted, it was like being hit by an Exocet missile. Soon consumers were sending it all their tattered clothes, whether Persil Power was to blame or not. The gig was up and despite reducing the amount of accelerator, nine months later Persil Power was no more.

Oh well. At least it was a brand add-on, not a replacement. Unlike New Coke. It's still extraordinary to think Coke was so rattled by the Pepsi Challenge that in 1985 it abandoned its original formula for a sweeter one. In their usual understated style, Americans took to the streets with 'Our children will never know refreshment' banners, prompting Coke to revisit its research and realise its mistake it had bestowed more faith in blind taste tests than in its own brand (factor the label in and the results were reversed). To its credit, it admitted its blunder, 79 days later bringing back original Coke as Coca-Cola Classic, and like Unilever, it learnt from its mistake.

These two infamous business nightmares show how easy it is to over-react to the competition. But at least they got away with it. The makers of the original Mini didn't. Taking on the Ford Anglia with a car that retailed at £500 £35 less than it cost to make, the Mini was a lossmaker from the start. Small car, monumental mistake.

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