SQL Server Integration Services (SSIS) - Checkpoint Restart-ability
Normally ETL operations are very complex in nature and time consuming process as it often deals with millions of records while pulling it or doing transformation on it. Now even if a package fails in middle of its execution; on next execution it will again start from the beginning, repeating all the tasks completed in last run.
SSIS provides Checkpoint restart functionality which simplify the recoverability of packages that contain complex operations and can provide significant time saving because the package does not need to reprocess all of the tasks prior to the checkpoint and will start from last point of failure.
Refer this link for more details.
https://www.sql-server-performance.com/articles/biz/SSIS_Features_And_Properties_Part3_p1.aspx