Functions


Introduction

SAS/QC software provides specialized DATA step functions for computations related to control chart analysis, for Bayes analysis of screening designs, and for sampling plan evaluation. You can use these functions in DATA step programming statements. The following lists summarize these functions:

Table C.1: Functions for Control Chart Analysis

Function

Description

C4

expected value $c_{4}$ of the standard deviation of a sample from a normal population with unit standard deviation

CUSUMARL

average run length for a cumulative sum control chart scheme

D2

expected value $d_{2}$ of the range of a sample from a normal population with unit standard deviation

D3

standard deviation $d_{3}$ of the range of a sample from a normal population with unit standard deviation

EWMAARL

average run length for an EWMA scheme

PROBMED

cumulative distribution function of sample median

STDMED

standard deviation of median of a standard normal sample


Table C.2: Function for Bayes Analysis of Screening Designs

Function

Description

BAYESACT

posterior probabilities of variance contamination


Table C.3: Functions for Sampling Plan Evaluation

Function

Description

AOQ2

average outgoing quality for double-sampling plan

ASN2

average sample number for double-sampling plan

ATI2

average total inspection for double-sampling plan

PROBACC2

acceptance probability for double-sampling plan


In addition, the PROBBNML and PROBHYPR functions, which are provided in Base SAS software, are useful when evaluating single-sampling plans.

The twelve SAS/QC functions, together with the PROBBNML and PROBHYPR functions, are described in the Function Descriptions section. The section Details, summarizes types of sampling plans and gives additional definitions.