RULES Subcommand (SPCHART command)

RULES specifies the rules for identifying out-of-control points. If a point violates any rule, it appears in the primary chart with a different shape and color compared to in-control points. Note that only the last point in a discovered pattern shall be marked for a rule violation, and any and all overlapping patterns are treated as separate patterns. A table of rule violations is also included in the output that displays the points marked in the control chart. If desired, use the ID keyword to specify the variable that identifies points in this table.

  • Any keyword may be specified in any place in the subcommand.
  • A duplicated subcommand name causes a syntax error.
  • A duplicated keyword is silently ignored.
  • The default keyword is ALL.
  • If the subcommand is omitted, no control rules are used.
  • RULES does not apply when generating a process capability chart (CPCHART subcommand).

ALL. All rules.

UCL. Greater than +3 sigma.

R2UPPER. 2 points out of the last 3 greater than +2 sigma.

R4UPPER. 4 points out of the last 5 greater than +1 sigma.

R8UPPER. 8 consecutive points above the center line.

R8LOWER. 8 consecutive points below the center line.

R4LOWER. 4 points out of the last 5 less than -1 sigma.

R2LOWER. 2 points out of the last 3 less than -2 sigma.

LCL. Less than -3 sigma.

TRUP. 6 consecutive points trending up.

TRDOWN. 6 consecutive points trending down.

ALTERNATING. 14 consecutive points alternating.