A measure of performance of self compacting concrete mixture in terms of engineering is proposed. This measure is based on the probability that a mixture prepared in view of a specified target remains in a given neighbourhood of that target. An application to a particular case of a self compacting concrete mixture desired by a precast factory is presented. The study involves previously a factorial design of experiments in a laboratory, the establishment of a statistical model for the response variables and finally the computation of the performance measure. The engineering robustness of the mixture is estimated in this particular case by means of bootstrap resampling and a bootstrapinterval for the estimate is given.