When editing the intervention schedule to add a new phase, the start date must be updated in order to generate a new phase/trend line. Otherwise, the intervention starting line and new phase line will overlap each other.
A phase line (also known as the intervention line) is a black vertical line on the progress graph that is meant to demarcate interventions and progress monitoring data collected using those interventions.
Once you have generated a new phase line, the updated intervention information will also appear in the table once data has been collected.
If you choose to update the existing phase and trend line, no new lines will appear on the graph. Instead, both your phase line and the intervention description on the table will be updated to reflect the changes you have made.
Note: If the intervention you are editing was created with a different setup form, please keep in mind that you cannot edit fields that are no longer extant. Because of this, you will see the new fields in addition to the old on the Progress Graph should you choose to update your phase line instead of generating a new one.
Neither choice will affect existing data.