Why is the decision to make a new toy not a quick and easy process for company?

Toy fads come and go - do you remember the cabbage patch dolls? With parents frantic to buy one for their ever demanding off-spring! If a company tries to foresee the next fad that children 'want it, as all their friends have got one!' they may guess wrong and have stock mouldering in their warehouses, or they guess right and have to put on extra shifts to keep up with demand. Yes, making a decision (without a crystal ball) is fraught with danger. And any company that guesses right, at least most of the time, will make a fortune.
Toy companies are constantly researching the market, studying the latest 'hit' movie, such as 'Frozen' and others that will suddenly bring forth the demand from children everywhere - until the fad wears off!