Assuming that the estimates don’t change at all, each day I would update time remaining. There may be times when I get pulled into meetings or other “on-project/off-task” activities, and I can’t allocate the predicted amount of time on that day. Or I may work from home one day, and in the absence of interruptions, dedicate more time to the task than was planned. Either situation would modify the relative time remaining, without necessarily changing the estimates of how much work is required.

However, and I think even more valuably, the estimates do change by tiny amounts every day. When the work for a given day allows me to accomplish more than I expected (it was easier than I thought, or I hit a groove, for example), then the amount of remaining work would be reduced by more than the amount of time spent. The converse is true for tasks that take longer than expected.

What makes burndown so powerful is the fact that we are always looking at what remains to be done. Imagine a runningback trying to score a touchdown. While he’s running, it doesn’t matter that he may have had to switchback behind the line to avoid tacklers – all that matters is how far he is from the end zone at that moment.

We can also use the data to review, reconcile, and improve our estimation process once everything is done. When our estimates prove to be off (in either direction), we have great data to help us understand why. And that understanding can be incorporated into estimates on future tasks / projects.

Thanks again, and welcome to Tyner Blain!
Scott