I’ve had multiple posts in the past that provided my passionate opinion on why I believe we should estimate Agile projects. (Both from the perspective of the client and the team) But rather than get into that discussion once again, I thought it would be more valuable if I shared the 10 practices that we have used over the past 6 years that have allowed our teams to successfully estimate Agile projects.
I work for a company that bids competitively on projects against other companies. In almost all situations we have to create estimates to provide to the client or else we would not be successful in winning the business. So estimating really is a fact of life for the type of business we are in. Although it might be nice to proceed on a project without an upfront estimate, that really isn’t a luxury we are provided. I believe we are in a similar boat to the majority of people out there.
Over the past 20 years I have honed my estimating skills with the experiences on projects. Over the past 6 years, this estimating has been predominantly for Agile projects. Although we have not been perfect in my estimating, I am quite proud of our track record and feel that we have been correct far more than we have been incorrect. Where we have been incorrect, we have augmented the estimating process so we won’t be incorrect in that way again.
The practices are not in order of priority as I had a real problem trying to do that as I think they are all important. So without further ado:
1) Remember to estimate Project Management and Technical Management
We frequently ran across missing these factors on early estimating attempts. This is usually done by everyone as they work on estimating as the work is easy to forget. It is a critical part of the estimate to ensure that these estimates are included so that we don’t scrimp on these tasks and cause larger issues for the project.
2) Don’t plan on your Technical or Application Architects being any more than 20% on construction tasks
This one continues to plague projects I estimate. No matter what the work is, the Architects will always want to work on their fair share of construction tasks. It is a noble desire and will return great benefit if they can work more on construction tasks. But I wouldn’t bet on it. In fact, I would even consider reducing this to zero depending on team size and complexity of the solution. If the Architects can work on more construction tasks, just consider that a bonus.
3) Remember to estimate for meetings and other factors in your schedule estimate
OK, now you have the estimates so lets just plan the hours out on the calendar right? Not quite. Remember to reserve some time every day for meetings, stand ups, and other non-construction activities. In addition, remember to plan for at least some time for vacations, holidays, and sick time. Use your statistics from your company to generate a rough factor for the project. It will just reserve a percentage of your schedule at the start, but then you will have the wiggle room when people start dropping like flies during flu season.
4) Hold a risk workshop and include the weighted estimates in the overall estimate
Mention Risk Workshops and most people yawn before you have completed the sentence. But they have great value. They are a great team building exercise at the start of the project as well. But ultimately, the output from the Risk Workshop should be used to generate an estimate and apply that estimate to the overall project estimate. By calculating the impact and probability of Risks occurring you will generate an estimate of the Risks that will likely occur. My experience is that if you don’t include these estimate, you will frequently address these risks occurring with Change Requests. The project can be much smoother if the estimate are included up front and you don’t surprise the clients. Yes, we won’t know all the Risks at the start, but it is better than assuming there are no risks at all. As Dr. Phil says “How is not estimating any Risks at all working for you?”
5) Estimate at multiple levels and triangulate
Probably the most important practice. We never just create one estimate. We typically estimate bottom-up (object level), deliverable (mid level), and top-down (schedule level). We use metrics for the bottom up and mid level estimates. (how long does a simple CRUD screen take, moderate report, etc..) Then we compare all three estimates and rationalize the differences. It is amazing how this rationalization uncovers estimating oversights.
We also then use Planning Poker sessions as we execute the project to confirm requirements and plan our iterations.
6) Proactively get information required to provide an estimate
Many times there are factors that may cause the estimate to change greatly. (Data Conversions, Legacy interfaces, unknown technology) Ask these questions early on and factor them into your estimates.
7) Say No when you don’t have information to provide an estimate. But be proactive and say what you need to provide an estimate.
If you don’t have the required information to properly estimate, then don’t. But don’t just say you can’t estimate. Provide the details of what information you need to be able to provide an estimate. I know on past projects we have guessed many times on estimates where in hindsight, the client would have gladly provided all the information we required.
8) Track estimates and actuals and use the metrics for future estimating. (both within the project and for future projects)
Yep. We need to track estimates. Sorry. These metrics will then be used to determine on average how long certain objects will take and the percentage that certain areas of the project will require. (Like Project Management!)
We also hold retrospectives and review iteration estimates and actuals so that we can revise our estimates as soon as possible within the project and taken them into consideration for future iterations.
9) Factor educated contingency into your estimates.
We have 17 contingency factors (and counting) that are weighted and applied. (at the team’s discretion) If nothing else, it is a least a checkpoint for the team to think about whether certain situations exist that may affect estimating. (new team? data conversion? new technology? complex interfaces?) Don’t just apply a standard 10% blindly to estimates. It has to be based on reality.
Like Risk, these contingency factors should then we applied to the estimate. I would also recommend that you don’t show what part of the estimate is Risk versus Contingency versus base estimate. Clients will then say that the contingencies won’t happen so just subtract that estimate. <sigh> The estimate is holistic.
10) Execute in a manner that respects that estimates are not actuals. They will be incorrect.
And after all the estimates are done, don’t execute in a manner that makes Captain Bligh look like a level fellow. Don’t micro-manage, realize that these were only estimates – some will be higher and some will be lower. Very rarely will any be totally correct. Let the clients trade requirements and stories as priorities change! You could not possibly know all the scope up front. But also don’t just agree to add new scope. A lot of issues about estimating do come down to good old-fashioned scope control. The estimate should be a guide and a placeholder for a discussion, not a roadmap.
My experience is that is we do all of these practices, our estimates will still be wrong. But much less wrong. More importantly, these practices help us to discover better ways of estimating. Discovering better ways doesn’t only apply to development practices, but all project practices. Ultimately these estimates also help the team members to feel better about their work as well. No one like to miss estimates and managing projects in a manner that respects that the estimates are not actuals will alleviate many of the negative connotations with estimates.
The correct thing is to fix how the estimates are managed, not to stop doing estimates.
P.S. I forgot one! Here is a bonus practice 11) Estimate that you will be wrong – remember to estimate for refactoring, defect fixing, and some rework. We are all good, but not that good.
Re-posted from http://bornagainagilist.wordpress.com