The 'Incremental Data Transfer' functionality was developed to be used when uploading the SCM system the first time with master data. In this case a huge amount of master data will be transferred to the SCM system. When an error occurred at the SCM system in the past the activation of the integration model had to be repeated after the cause of the error had been resolved.
In this case all the data assigned to the integration model were transferred again to the SCM system what might have taken again a lot of time. In addition, you had to make sure that the settings for all transferred data were o.k. at the SCM system to get the model activated.
With the incremental load only the blocks with errors will not be updated at the SCM system. For all other blocks which are fine you will find an active integration model at your ERP system afterwards. In addition, an inactive integration model, which contains all data of the original integration model, is created.
After you resolved the cause of the error you can simply activate the latest inactive version of the integration model as usual and only the data for the missing blocks will be transferred to SCM system instead of all data because of the delta logic.