Assume that an automotive company produces 2 000 000 electronic engine controllers of a special type. The following design alternatives are discussed:
(i) Construct the engine control unit as a single SRU with the application software in Read Only Memory (ROM).The production cost of such a unit is 250 $. In case of an error, the complete unit has to be replaced.
(ii) Construct the engine control unit such that the software is contained in a ROM that is placed on a socket and can be replaced in case of a software error. The production cost of the unit without the ROM is 248 $. The cost of the ROM is 5$.
(iii) Construct the engine control unit as a single SRU where the software is loaded in a Flash EPROM that can be reloaded. The production cost of such a unit is 255 $. The labor cost of repair is assumed to be 50 $ for each vehicle. (It is assumed to be the same for each one of the three alternatives). Calculate the cost of a software error for each one of the three alternative designs if 300 000 cars have to be recalled because of the software error (example in Section 1.6.1). Which one is the lowest cost alternative if only 1 000 cars are affected by a recall?