Contengency means unexpected event and the contingency plan is the critical output of the migration planning phase. It defines the action plan when the case occurs especially during the migration period. The tons of cases can assumed from very tiny one like missing person, small bug of the migration program to the tragidy level like serious earthquake. This plan tends to be considered less seriously because everybody hopes the case not occurs as the cut-over timing comes by. So it needs to be shared with all stakeholders from the very biginning of the project even with the draft level.