This lab will show you step-by-step how to use the Flat File Disassembler, Delivery Notification, and a Sequential Convoy to map a large flat file document.
Get more information from the original blog post on this topic: https://www.biztalkgurus.com/biztalk_server/biztalk_blogs/b/biztalk/archive/2005/06/12/sequential-flat-file-message-processing-lab.aspx