Three sets of parallel R&D projects are examined. The data analyzed were gathered by means of Solution Development Records — a form which provides a weekly estimate of the probability of adoption of the approaches under consideration as possible solutions to a technical problem. It is found that the longer an approach is held in a favored position, the more difficult it is to reject. Furthermore, the number of alternative technical approaches considered bears a relation to judged solution quality. Groups producing higher rated solutions generated fewer approaches during the course of the project, and they more closely approach an ideal strategy of trading approaches off on a two-at-a-time basis than do their poorer performing rivals.
Allen, T. J. (2013). Studies of the problem-solving process in engineering design. IEEE Transactions on Engineering Management, EM-13(2), 72–83. https://doi.org/10.1109/tem.1966.6447087