The Importance of Time Completed and Time Remaining in Estimations

importance-of-estimates-time-completed-time-remaining/One of the first things many team members on Agile projects lose sight of is the importance of tracking their time spent on their tasks identified in their Backlog Item. Whether it’s a User Story, Sub-Task, Enhancement, etc., logging hours spent is of absolute importance to make sure further Sprint burn-downs, velocity, and estimates will continue to reflect increasing accuracy. The tendency of some teams is to use their Backlog Items (in either of the forms mentioned above), as a scope tracker. However, time-tracking on a daily basis is of absolute importance.

How Your Hours Should Really be Logged

Once a backlog item has been completed, only then do team members log their hours, and it most likely ends up being the hours set in the original estimates. Not only is it best practice to log hours spent on your backlog items on a daily basis, but also to re-assess what the remaining hours are. Just because an item was estimated to take 16 hours, and you performed 8 hours so far, it does not mean 8 hours remain. Sure it would seem logical that it would come down to a simple mathematical equation, but it’s truly not what is meant by “Time Remaining!” So what should be put in Time Remaining? It’s really about what should be required to complete the task at the moment of logging your time mid-course. What that means in our previous example; if you logged 8 hours for a task that was originally estimated at 16 hours, you may come to realize, there’s only 4 hours left. It’s as if you are re-estimating or re-assessing what is left to do. A number that does not match what was originally estimated, is perfectly fine either from a downward estimate or an upward one (assuming it’s done correctly of course!). This is by far the best way to know if original estimates were done accurately, and gives team members a gauge on whether those estimates continue to be assessed correctly in later sprints. Better yet, if needed, the variance of estimation accuracy can be calculated as well.

When Time Remaining is Not Taken Seriously

The problem arises when developers mark down remaining estimates as a straight-line mathematical equation, since it would imply that all original estimates were done properly, and makes it impossible to weed out the estimation imperfections during Sprint Planning from Sprint to Sprint. The other issue that may happen is that there could be a skew in estimations since some developers will take their time to complete a task (if they see that they’ve completed it early), and then hurry their task, or worse, bust the estimates if the task was underestimated. From there, it may escalate to having only underestimated tasks as being incorrectly estimated. What that gives is a mix of underestimated, and on-time estimates. As you can see, when the hours are totaled up for that sprint, the skewed results give an impression that generally all tasks were underestimated, and the lack of transparency will make the team draw separate conclusions. This also affects your burn-down charts and interpretation of velocity, all the while the cycle of trust within the team is broken.

How This Helps Continuous Improvement

Seeing the above situation in a different light, if you were on a trip where the original travel time was supposed to be 10 hours, only to find out the ride is shorter than expected, you would probably want to know, right? The same would apply if it would be longer than expected. To make the point clearer, your expectations, and that of others depend on the transparency of what remains to be done on any development effort. This aids efforts for future estimations and weeds out any further potential to be disappointed.

The next time you may be faced with a seemingly obvious question “How much time is remaining?” it may need to be seen as “How much time is needed to complete the task?” It’s not just a simple math calculation. Remember that estimates are called “estimates” because there is a chance that they will not be “accurate.” Having those numbers accurately represent “time remaining” allows for the estimation process to get better and better, as the team looks back in retrospect and compares their estimations for future Sprint Planning sessions.

 [Image courtesy of lekkyjustdoit at]

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