A number of factors affect the success, or otherwise, of any technological innovation. In this paper, we consider factors that affect the success of innovations in the context of forest machinery manufacturing (FMM). We report the results of a study that seeks to determine the relative importance of 19 different factors affecting the success of innovations in the FMM sector. The first stage of the study makes use of the analytic hierarchy process to determine the relative importance (weights) of these factors, based on the responses of 15 decision makers (DMs) employed by different FMM companies. The study then considers three different ways of weighting the responses of DMs, based on different assumptions about how the responses of outliers—those DMs whose views differ significantly from the majority—should be handled. The first method assumes that the responses of all DMs are of equal value. The second assumes that the influence of outliers' responses should be reduced and makes use of a Euclidean distance metric to determine the weight that should be ascribed to each DM's responses. The third assumes that the influence of outliers' responses should be increased and makes use of hierarchical clustering techniques. Although the weight assignment methods were based on very different assumptions about how to treat the views of outliers, they produced similar rankings of factors. Results showed that for FMM companies, customer satisfaction, proportion of total sales by new products, influence on the overall profit of the company, and growth of demand for the company products were the most important factors for measuring the success of innovations.