Hi Liz,

I'm afraid the scenario isn't going to work. % Complete is a duration measurement - so if you change the finish date (increase duration) Project will automatically drop the % complete. Even with manually scheduled tasks, changing the finish date to a later date will drop the % complete.

You may be able to come closer using % Work complete and fixed work tasks. If you set your tasks as fixed work - and you adjust duration - project simply recalculates assignment units.

Julie