If the ECP pertains to an existing approved program, no new documentation would be required.  However, the documentation that already exists for the baseline program would need to be reviewed and updated as required/directed. The documentation could be updated with an annex or enclosure, addressing those changes due to the ECP.  At a minimum the configuration management plan and the life cycle sustainment plan (LCSP) should be updated.  The approval process for the updated documents would be the same as the original documents and should be outlined in the program's charter.  There is no requirement to create new documents simply for the ECP, unless directed by the milestone decision authority (MDA).  As long as form, fit, and function are not affected and force effectiveness, survivability, and lethality are not affected, there should not be a requirement for any additional testing or LOG Demos.  However, an excursion to allow a short user evaluation might be useful and beneficial to ensure that no changes to training manuals, documentation, and procedures are required.