The use of ECU software in cars has grown considerably in recent years. To more tightly manage the development costs of software suppliers, as well as its own validation activities, Renault SAS measures the functional size of our ECU software specifications using international standards, and uses this information as the main input for estimating software development costs and schedules.

The COSMIC functional size measurement method is a standardized method for measuring the functional size of software. To obtain this size and reduce measurement differences caused by interpretations of individual measurers, we propose a functional size measurement (FSM) procedure for real-time embedded software with specifications modeled using Simulink. The design of this FSM procedure is based on the mapping of key concepts in both Simulink and COSMIC and on the identification of the mapping rules for extracting required information stored in the Simulink files. This procedure has been implemented as an automated measurement tool for software requirements specified using Simulink. This COSMIC functional size measurement tool has been applied at Renault SAS on real ECUs.

This session presents the design of the FSM procedure based on the COSMIC method to obtain the functional size of software specifications expressed with Simulink. This includes COSMIC rules tailored for Simulink models and the explanation of the mapping of the Simulink concepts to the COSMIC concepts. This session also presents the automated measurement tool developed at Renault SAS for implementing this approach and its application on real powertrain ECU software models.