The MUSiC Performance Measurement Method is used to validate the final quality and usability of a system for the end user. Quantitative goals can be set and evaluated, and feedback obtained to improve the design. It is based on a procedure for analysing user behaviour, supported by a video recording.
The method gives reliable measures of the effectiveness and efficiency of system use, by evaluating the extent to which specific task goals are achieved, and the times taken to achieve them. It also gives measures of time spent unproductively plus valuable data about the source of such difficulties. These measures enable comparison of prototypes of alternative designs with earlier versions of a system, for example, or with competing products. The diagnostic information helps identify where specific problems are encountered and where improvements need to be made. A major benefit of using MUSiC methods for usability measurement is that they provide a means of specifying usability goals and evaluating whether they have been achieved. The goals are expressed in terms of the purpose of the business system which is to enable users to achieve tasks effectively, efficiently and with satisfaction. It is possible to measure; whether typical users can correctly complete the task; the efficiency of typical users; how the efficiency of typical users compares with an expert user: this gives an indication of the point on the learning curve and may highlight a need to improve the user interface or to provide more training; the proportion of the time for which a user is productive: this may also highlight a need to improve the user interface or to provide more training. It is also important to measure user satisfaction, particularly as poor satisfaction is likely to lead to future deterioration in performance..