One weakness of the product life cycle is that it isn't set up for innovation. If your product doesn't operate for a full life cycle, you'll have to replace it over and over. That can be more costly than keeping the product for a long time and then only replacing it when a newer, better model comes along. Another weakness is predictability. That becomes dangerous, because competitors know what each company or individual in competition with them is likely doing. In order to break that knowledge and change the market, a company has to create something completely new and unexpected – which may or may not catch on in the marketplace. It's a huge risk that doesn't always pay off.