Optimum Redundancy of Repairable Modules

The design of modules to have some redundant functions in order to minimize module production cost is analysed. Upon production modules with failed functions are either discarded or repaired. If some functions have 2 elements in parallel, the production cost of a module can be minimized if modules are discarded or repaired, depending on the number of redundant functions, number of functions per module, element costs and element quality. The number of failed functions above which the module is discarded rather than repaired is calculated using a simple computer algorithm.