On a problem in two-stage sampling

Beattie 1962 proposed an alternate procedure for monitoring continuous processes which, unlike existing continuous samplingplans under Mil-Std-1235B, does not require periods of 100% inspection. The procedure, which is a composite of two Cumulative (Cusum) procedures, will be analyzed in terms of Cusum average run length (ARL) performance. An algorithm is proposed for generating sample plans based upon specifications on ARL performance in each of the Cusum sampling zones and the overall sampling risks of the procedure. The algorithm is fully described, and implemented using exact expressions for the Cusum ARL. An illustrated example is provided, describing how a continuous sampling maybe selected which matches performances about the AQL for a related plan in ISO 3951.