If Wally has been adding an assignment a week to his schedule for, say, 15 years, without ever completing anything, then his plan must be something to behold by now. Just as a sop to PHB, perhaps he can now just put those tasks which over the years have become irrelevant at the front of his plan, and show progress over the next year by confirming that everything necessary with respect to them is complete. Meanwhile, the assignment he was given today will need to take its turn at the back of the schedule, maybe five years in the future.