What are at present the major obstacles that hinder the deployment of more advanced embedded systems within a car? We have identified five key interlinked obstacles: (i) Electronic Hardware Cost: Hardware costs are recurring costs that are decisive for the economic success in a mass market. Since in today’s system a new node (ECU–electronic control unit) is required for nearly every major new function, the hardware costs escalate significantly with every additional electronic function. (ii) Diagnosis and Maintenance:
The diagnosis of transient and intermittent component failures, which are the major cause of system outages is insufficient. For example, it has been reported in  that more than 50% of the supposedly failed electronic modules removed from vehicles and returned to the supplier, passed bench tests. (iii) Dependability: The replacement of mechanical subsystems by electronics requires a level of electronics dependability that is higher than the dependability of the mechanical subsystems that are replaced. Such a high dependability can only be achieved by the provision of fault-tolerance.
The On the Fault Hypothesis for a Safety-Critical Real-Time System 39 number of physical contact points, which are a main cause of system unreliability, must be reduced. (iv) Development Cost: The unintended side effects between different application subsystems increase significantly the development and integration efforts. Changes in one subsystem often effect the operation of another subsystem. The unproductive glue code needed to support the communication of ECUs located in different networks is substantial and growing.
At present the interfaces of many subsystems are ill-specified in the temporal domain . As a consequence the modular certification, the reuse of software components and the ease of integration are severely compromised. (v) Intellectual Property (IP) Protection: Suppliers in the automotive supply chain are reluctant to open their IP which is contained in a compiled software module to OEMs or other suppliers in order to maintain their competitive edge.