In some cases, the source data may contain the complete order instead of just the delta changes. In others, some lines might be removed from the source system that are still in your NetSuite line items. Nonetheless, you might want to remove all the existing lines and add all the lines from your source data into NetSuite.
To enable this setting, add a new import field mapping for Items : Replace All Lines, and hard-code the value to True. Each sublist on the parent record should have a similarly named mapping option available.
