Statistical Quality Control By Mahajan.pdf Page

Acceptance Sampling is reactive. It involves inspecting a random sample from a batch (lot) to decide whether to accept or reject the entire batch.

For (\barX) chart:
[ UCL_\barX = \bar\barX + A_2 \barR, \quad CL_\barX = \bar\barX, \quad LCL_\barX = \bar\barX - A_2 \barR ]

For R chart:
[ UCL_R = D_4 \barR, \quad CL_R = \barR, \quad LCL_R = D_3 \barR ]
(A₂, D₃, D₄ are factors depending on n, given in standard tables.) Statistical Quality Control By Mahajan.pdf

A recurring theme in Mahajan’s work is ensuring that the process is actually capable of meeting the engineering tolerances.

The text introduces indices like $C_p$ and $C_pk$. Acceptance Sampling is reactive

If a machine cannot physically hold the tolerance required, no amount of control charting will fix the problem. The process must be redesigned.

Take k samples of size n (usually n = 4 or 5) at regular intervals. If a machine cannot physically hold the tolerance

Statistical Quality Control (SQC) involves the use of statistical methods to monitor and control processes to ensure that products meet certain quality standards. It encompasses various techniques for identifying variations in processes and products, thereby enabling corrective actions to maintain or improve quality.