Report calculations

Real-Time SPC uses the following equations to summarize and report the quality metrics on your dashboards. Use Manage Columns to show/hide various metrics on the Current Performance Summary and Supervisor Dashboard.

For each measure:

For the overall station:

%Out-of-Specification = 100* (1−(1−OOS₁) * (1−OOS₂) * … * (1−OOS_n))

%Out-of-Action = 100* (1−(1−OOA₁) * (1−OOA₂) * … * (1−OOA_n))

%Out-of-Control = 100* (1−(1−OOC₁) * (1−OOC₂) * … * (1−OOC_n))

Measure Averages = The displayed measure average for a station is the maximum observation measurement average at the station.

Example of station out-of-specification calculations:

This example shows a station that has an overall % out-of-specification = 56.25%. Each of the measurements show the number of subgroups out of the total that are out-of-specification.

Station %OOS	56.25%
Measure 1 %OOS	*
Measure 2 %OOS	*
Measure 3 %OOS	25.00% (1/4)
Measure 4 %OOS	25.00% (1/4)
Measure 5 %OOS	22.22% (2/9)
Measure 6 %OOS	0.00% (0/3)

Net content calculations

For each measure:

For the overall station:

%Out-of-MAV = 100* (1−(1−MAV₁) * (1−MAV₂) * … * (1−MAV_n))

%Out-of-T2 = 100* (1−(1−T2₁) * (1−T2₂) * … * (1−T2_n))

%Between T1-T2 = 100* (1−(1−(Between T1-T2)₁) * (1−(Between T1-T2)₂) * … * (1−(Between T1-T2)_n))

%Out-of-T1 = 100* (1−(1−T1₁) * (1−T1₂) * … * (1−T1_n))

%Overfill = Max of the measure %overfills. The %Overfill can be negative values that represent percentage underfill. With multiple measures, the station %Overfill displays the largest overfill value. If any measures have negative overfill values (underfill), then the station displays the most severe underfill.

If %overfill for 3 measures are 3.4%, 2.8%, and 6.0%, then %overfill for the station is 6.0%.
If %overfill for 3 measures are 4.9%, -2.3%, and 6.2%, then %overfill for the station is -2.3%.

For more information on limits, go to Specification limits and Net content limits.