One of the most difficult and consequential steps in any project is effort planning. Before I introduce the effort estimation method known as Planning Poker, I want to share a few important points to keep in mind:
- To create a reliable effort estimate, you need to have a fairly clear picture of what you must deliver — otherwise you are just guessing. Not knowing exactly what needs to be delivered can mean you have no experience with what you are taking on, or it can mean your client does not really know what they want.
- If you have never built or delivered anything similar before, you risk being way off with your effort estimate. Experience cannot be replaced by anything — including the method described below.
- If you think something will go much faster this time than last time, you should have a sober rationale for that. New tools and methods do not count.
- In some technology domains, the performance of individual team members plays a significant role. Particularly in knowledge work, productivity differences of 500% are not unusual. Except in very large teams where these differences average out, you should know your team members and involve them in effort estimation.
- Do not negotiate down the effort estimates your team members provide. As a rule, employees tend to underestimate the friction that will arise and overestimate their own productivity.
Planning Poker is an interesting method for arriving at robust effort estimates for time and cost in projects — once you have taken all of the points above into account. The prerequisite for a Planning Poker session is a list of desired project deliverables, for example in the form of requirements. These must be described precisely enough that the estimators can understand what is being asked.
For the Planning Poker session, the estimators meet under the guidance of a moderator. Each estimator receives an identical deck of cards. You can buy such cards; one vendor uses the numbers 0, 1/2, 1, 2, 3, 5, 8, 13, 20, 40, 100 as well as a ? to indicate that an estimator does not feel able to provide an estimate. The numbers can represent effort in days, or stand in some other predetermined constant ratio to the actual effort.
At the start, a product manager presents the project deliverables to be produced — for example as defined with the help of project management software such as Allegra. The team can ask questions if anything is unclear.
The team members then estimate the effort. Each team member places their card face-down on the table. Once everyone has placed their card, the cards are turned over simultaneously and the estimates are revealed to all team members.
The estimators with the highest and lowest values are given the opportunity to explain and justify their estimates. The group can discuss what has been put forward. The discussion time can be limited by the moderator or project manager.
The estimation process followed by discussion is repeated until the group reaches a consensus. Throughout this process, the estimator responsible for delivering a particular piece of work always carries more weight than the other participants.
The card numbering reflects the fact that the larger an estimate is, the greater the estimation uncertainty. This means that for larger values, an estimator cannot feign false precision — they must commit to either a pessimistic or an optimistic value.
Further Information
Read more about agile practices, find more information about agile project management here, and discover the best agile project management tools.
Editor and Writer
Gabriella Martin is a Yale University graduate and holds a Master's degree in German Literature from the University of Tübingen. She loves explaining complex things in simple terms.
