On many projects, the question I many times hear is “how much time have you spent?” Time tracking systems are often created to track time spent. This seems logical and often times people do not think twice about it, but it is one of the leading factors contributing to late projects. Let’s look at an example.
On a project I have a task that I estimated at 10 hours to complete. On the first day I spent 3 hours on it and on the second day I spent an additional 2 hours on it.
Question: How many hours do I have left on this task?
Answer: This is simple math. I estimated the task at 10 hours and spent 5 hours, so I have 5 hours remaining.
And herein lies the problem. Spending 5 hours does not necessarily mean that there is 5 hours left. It would be correct if my initial estimate was correct, but this is often time not the case. This inaccuracy gets larger as the task gets larger (ex. 1,000 hours). Unless you have done this task before and you don’t encounter any roadblocks, it is unlikely that you can estimate every task with accuracy. Additionally, there are many unknowns that may prevent you from achieving your estimate. What if the system that you are working on is having issues? What if the power goes out? What if you didn’t realize one of the things that you needed to do and didn’t include it in the estimate? What if the task changed mid-way through because the customer changed their mind? There are a variety of reasons as to why this situation may occur. As a result, it is more important to look at time remaining.
Real Answer: Estimate how much time is left, given the work remaining and uncertainty left with the task. In this case I spent 5 hours, but think I have 7 hours left, for a total time of 12 hours on the task.
Keep this in mind next time you are working on a project. We know the least at the start of something and we know the most at the end. So it only makes sense that your initial estimate may be incorrect. Update your estimate as you learn more and provide more accurate status by looking at the time remaining, not time spent.