What is the ultimate goal of a project manager ?
It's a very hard one : somehow, it consists in predicting the future and ensure that projects are completed on time and within budget without sacrificing quality. Various feedback from different industries all show the same trend : overcosts and costly delays are more than common and the more complex the project the worst the situation.
I'd like to share my experiment with a tool borrowed to agile project management techniques on a fixed price contract : the burndown chart. It helped me to get more insights on how things went on and to fix the issue. In order to maximize the value, I'll illustrate the experiment with 2 case studies, and provide the data within an Excel spreadsheet.
The bundown chart is... A chart which shows the evolution of the Estimate to Complete (ETC) over time, and compare it against a theoretical progress. The curve decreases over time.
A more detailed description of the concept is available on Wikipedia.
Why it helps ?
Why would you using a dumb chart in Excel instead of relying on your favorite scheduling software ?
Even if you're using your favorite scheduling tool every day/week to know where you stand, the only it provides you with is a snapshot : It answers to the question "Will I be able to achieve the target deadline ?". It's not helpful to get more insights at a glance.
Looking to the burndown chart is like looking at a video instead of a set of pictures, trying to guess what happened to a character who disappeared.
It allows to answer at a glance to the following questions :
- What is the trend of reestimated workload ?
- If I can't achieve the target date, when will I be able to achieve it ?
- Is my schedule predictible ?
- Is there a resources issue on the monitored team ?
It's build on the same data
The burndown chart can be easily built by exporting data from your favorite scheduling software.
- Ensure that actuals and ETC have been reestimated by your teams for the previous day/week
- Reschedule to update target dates without overloading resources
- Export data to Excel to record the current day/week forecast
It's easy to read
Reading a chart is maybe less accurate but much simpler to understand at a glance than a set of figures.
Burndown chart let you experience the "flow" of charting as traders can experiment. You can easily perform a visual regression to "guess" the most probable delivery date given the trend on the chart.
Case study #1 : The "goes unpredictible" schedule
I recently experienced an issue with a team managed remotely. After a period where target date hadn't moved, dates began to shift each week. Let's quickly analyze the issue with the burndown chart tool.
We can see that schedule began to become unpredictible on 27/02/2012. A slow down in ETC decrease is noticed, but by analyzing reestimated workload, we know that resources have not been directed to other tasks. Reestimated workload started increasing each week.
That meant that issue was not only a delay, but we also had an overcost to be dealt with.
This quick detection allowed to implement an action plan which conducted to obtain a more accurate ETC.
Case study #2 : Diverted resources
Lets take a similar case, but this time, team is well managed : commitment on initial workload is achieved. However, we can point out on the chart that :
- Resources are on-boarded lately. This entails an initial delay.
- Initial delay is catched up by adding 2 more resources to the team. On mid-February, the project manager is confident that the phase will be completed on time and within budget.
Unfortunately, upon customer request, higher priority work has to be performed on another project due to issues on production system. Resources from current project are diverted to these activities, entailing a shift in the schedule. The burndown confirms that delay is entailed by a resources shortage, and not because of a lack of predictibility on weekly estimates.
Burndown chart is a powerful tool, because of its ease of use as well as because it relies on historical data. It enables to diagnose situations at a glance, and help better decision making.
Burndown chart applications can also be extended using its historical data comparison to initial estimates, and statistical tools such as regression techniques, to remove biases from estimates and obtain more accurate estimates, therefore duration and schedule.