  The most popular tool used in the industry for monitoring a process is the
Shewhart control chart. The major disadvantage of the Shewhart control chart is
that it is not very efficient in detecting small process average shifts. To
increase the sensitivity of Shewhart control charts to small shifts additional
supplementary runs rules has been suggested. In this paper we introduce and
study the modified r/m control chart which has an improved sensitivity to small
and moderate process average shifts as compared with the standard Shewhart
X-bar control chart and corresponding control charts proposed recently in the
literature.
