Abstract: A measurement mechanism which can be implemented in any complex system for measuring the service times required for carrying out specified operations is described for a system having a plurality of components working in pre-emptive mode so that an operation once started by a component can be suspended to perform other operations which are requested by the same or other components if these operations have higher priority levels. The measurement mechanism includes a current status register 16 in which the system causes a status value to be stored representative of the current operation being performed by the system. It also includes a reference status register 18 in which a reference value representative of the operation to be measured is stored. These values are compared through a compare logic circuit under control of a filtering value stored in another register. When a match is detected by the compare circuit, the content of a counter is incremented.