Datapolis Process System
Workflow Auto Cleanup
By default, Microsoft SharePoint Foundation 2013 runs a daily “Workflow Auto Cleanup” job to permanently delete workflow instances and related task entries that still exist 60 days after a workflow is completed or canceled. Workflow history items themselves are not deleted, but the entry point to view them on the status page for a particular instance of a workflow will no longer be available.
To disable timer job cleaning workflow history information, follow the below steps: