Effect of parallel planning on system reliability of real-time expert systems

Real-time expert systems (RTXS) are expert systems embedded in process-control systems which must plan and execute control strategies in response to external events within a real-time constraint. This paper presents a method for estimating the reliability of uni-processor and multi-processor RTXS. The paper discusses why there are intrinsic faults in RTXS programs that must be considered in their reliability modeling. Then, it shows that for uni-processor RTXS, no single planning algorithm can avoid all types of intrinsic faults. Finally, it presents a multiprocessor architecture with parallel planning with the objective of reducing intrinsic faults of RTXS and improving the embedded system reliability. A robot control system illustrates the method