Fashion group, Next, was punished last week for backing a loser. The group - one of the most dramatic turnaround tales on the High Street - saw a quarter of its stock market value eliminated as it admitted aiming too many of its garments at young trendies and too little at thirtysomethings with more expansive wallets.

The UK chain, which has stores in Grafton Street and The Jervis Centre in Dublin, has had too many lingerie dresses and micro minis on its rails and far too few tailored business suits for office workers and daily wear jumpers.

The result has been a fall in sales which will leave profits below last year's levels and a deep suspicion in financial circles that Next, with an unblemished record for seven years and regarded as one of the best high street operators, has lost the plot.

But Next is far from a unique fashion victim in today's retail world where the earnings power of new "concepts" is about as reliable as the trajectory of a comet.

Look only at Laura Ashley, Next's faded rival. Two years ago, the ailing frocks and furnishings empire whose brand image was firmly stuck in the 1970s imported Ann Iverson, an American retailing professional. She swept out the old and installed a new sophisticated range of clothing and home furnishings. It didn't work. New shoppers stayed away and old customers were alienated by the new ranges. Ms Iverson has now exited and Laura Ashley is fighting for survival.

Fashion firm Alexon caught the end-1980s "leisure wear" bug and expanded its Dash brand of tracksuit-inspired clothing just as it was becoming viewed as deeply demode. Etam suffered a similar fate when it earned a tag as purveyors of style to the young ladies of Essex.

Even Marks & Spencer has occasionally had to accept a cut in its profit margin by putting more goods in the sales than normal.

Next chief executive David Jones believes last weeks reaction - shares tumbled 173.5p to 544p last Thursday - was overdone. "Rather than saying aren't we naughty for making a mistake after seven years, people should say haven't we done well not to have made a mistake for so long." Next shares closed yesterday at 579p, up 29p.

The fickle finger of fashion affects not just the clothing business. Look at the Irish pub chains such as Filthy McNasty, O'Neills and Scruffy Murphy's. At one time, there seemed to be no stopping the conversion of English pubs into pseudo-Irish outlets. Now, insiders say the pulling power of Irish pubs is substantially diminished and the concept is being modified to pep up its appeal.

There is a substantial lead time to almost every type of produce. For Next to put new ranges of suits in its shops, says Mr Jones, will take up to 28 weeks - 18 weeks for the cloth to be ordered and delivered and up to a further 10 weeks for manufacturing. And 50 per cent of Next's clothing is made in the UK, where delivery times should be shorter than for garments from Asia.

Christmas toys are sold at industry fairs at least 10 months before they hit the shops and production starts more than 18 months in advance. A second generation of Teletubbie toys, for instance, was being planned before the first toys showed any signs of being such a huge success.

Record companies can pay huge advances to new artists who take so long to put down an album that tastes have changed before they can get a follow-up record on to the shop shelves.

Businesses have to take huge gambles that their investments will pay off. It is hardly surprising that sometimes they make a big mistake.