Exposes the system to a significant change with associated risk. The look and feel of the system is changed. Increases the complexity of configuration management with parallel production enhancements. Test requirements are as for a major system change, and may require special considerations such as dedicated test regions. Testing with future system dates may necessitate an isolated or virtual host.
Project is large.
Management is critical. The sharing of copybooks creates data dependencies which make it difficult to isolate program changes. Each conversion event is likely to impact a sizable portion of an application or a whole application, or will require intra-application bridging software. The sorting of date fields will be a serious problem It is possible to change the collating sequence using sort utilities if that is necessary. Some sorts are to group related items, and may not need to sort 00 after 99 in any case.