The need for fault isolation in object-oriented control systems

This report discusses the problem with fault propagation in large scale control systems with object oriented architecture. There seems to be a trade-off between the degree of object encapsulation and the possibility of suppressing propagating error messages – when an individual object detects a fault, it does not in general know how close it is to the real fault, and hence whether it should report an error to the operator or not. Mechanisms for querying other objects on-the-fly is feasible only for closely related objects due to OO architecture goals.