The paper proposes a model of innovation claimed to be applicable both to the lone entrepreneur and the large institution. It treats innovation as a social process and views it in some respects as analogous to natural selection.The model takes into account 12 elements: the innovator, the new concept, the innovating group, the new product, target user, competitors, capital supply, strategy, supplying organization, technology, relevant environment and chance. The author characterises each element and shows how they interact in the course of guiding a particular innovation to success or failure.The operation of the model is illustrated by applying it to two cases — the rise and decline of the metal ski and the launch and success of a national US newspaper.The paper concludes with a list of possible uses of the model, as a checklist for action, as a basis for incorporating other approaches to the innovation process and as a starting point for a quantitative representation of the innovation proces