Estimation of Real-Time Software Component Size

For distributed networks which will be mass-produced, such as computer systems in modern vehicles, it is crucial to develop cost-efficient hardware. A distributed network in a vehicle can consist of 100 ECUs (Electronic Control Unit). In this paper we consider the amount of memory needed for these ECUs. They should contain enough memory to survive several software generations, without inducing unnecessary cost of too much memory. We show that UML Component Diagrams can be used to collect enough information for estimating memory size using an FSM method. We develop two linear models capable of estimating memory size for two common types of software components before the software is available. We support our findings by two experiments containing several software components from the automotive industry