You may need to update individual data observations to fix data entry errors or update assignable causes and corrective actions. Both the Station Dashboard and the Process Quality Snapshot in Real-Time SPC provide access to the individual observations via the control charts.

What happens when I update individual observations?

The editing of an individual observation follows the same workflow as entering a new observation, and the calculations and flagged points are updated with the new data. When you update an individual observation, the following items are also updated.
  • The plotted points of a control chart are updated, including the updated point and any associated subgroups.
  • The tests for special causes of a control chart are rerun.
  • The summary and performance statistics are updated.
  • If the original data point was flagged and had assignable causes and/or corrective actions, these will remain if the point still exceeds the limits. If the point no longer exceeds the limits, the flag, assignable cause, and correctives are removed.

    Control chart points with assignable causes are not used in the control limit calculations.

How to edit individual observations

In this example, the supervisor reviews the Process Quality Snapshot and notices that a pH measurement was recorded incorrectly.
  1. Open the control chart that contains the observation that you want to edit. You can access the control charts from the Station Dashboard or the Process Quality Snapshot.
  2. Select the plotted point to edit, then open the details pane.

    Under Individual Observations, select Edit to open a dialog to edit the data observation or descriptor value. You can also update the assignable causes and corrective actions and add any additional comments.

  3. If you want to edit only the assignable causes, corrective actions, or comments for the entire plotted point, select Edit in the flagged point box.

Edit descriptors

Subgroup descriptors
You can edit the data for the subgroup descriptors. These values apply to every observation in the subgroup.
Individual descriptors
Under Individual Observations, select Edit to open a dialog to edit the data observation or descriptor value.
For more information on descriptors, go to Use descriptors.