This paper describes a new method of evaluating relatively the performance of a task which is repeated many times, by using a work achievement quotient. The method is better than the usual analytical ways using the mean value or the standard deviation, because the performance is evaluated relatively in the interval [0, 1]. A development of the method which evaluates the work relatively and dynamically, using a tendency equation, is also discussed. These methods comprise the research and review system (RS) method. As an example of their application, the performances of three employees of an automobile company in repairing a fork-lift truck are compared.