Somewhere in excess of 90% of new products developed are ultimately unsuccessful and often the development of a new product is expensive relative to other activities in the firm. Consequently there is a great deal of wastage in the development of new products. So you want to give yourself the best chance of success and not spending time and resources on products that will ultimately fail. Having a set out and rigorous (but not complex!) development process can help. Broadly the stages in a process could be: