Milestone Estimations

Despite our dislike for estimates due to their inaccurate nature we still do them in some form because the reality of the situation is that we need to know relatively early in the process if we are going to be able to hit a timeline or not. Obviously we can't know this 100% because as we have stated estimates are very inaccurate. However, they can gives us a pulse to know if we think we are significantly going to miss a timeline. This is crucial as that pulse is what instigates pruning of non-crucial features and setting expectations appropriately with the client.

To facilitate this we of course start with the initial estimates from the Discovery & Definition phase. However, things have likely changed since that time and the developers haven't thought about the complexities of each of those milestones.

To facilitate this when a Journey is reviewed by product with the associated dev team. The dev team goes back through the milestones of that Journey and puts together estimates based on the following thinking.

Origination of Thinking

Historically we have focused on the concepts of Complexity and Effort while putting together estimates and it was only our Milestone Planning that thought about unknowns and risk.

However, relatively recently Theo dropped a video where he broke down what he has thought of for a system for estimates. It is very much in alignment with our current approach as it takes Complexity and Effort into consideration. However, beyond that it takes into account Risk and goes through the reasons for estimating in a more analytical fashion. Therefore, we have effectively adopted his approach with some small tweaks.

We also differ from his approach in that after thinking through these characteristics we then estimate how long things will take (in developer days) using these characteristics guidence. This is critical for us to understand how we are making progress in terms of our estimates so that we can make adjustments and manage client expectations appropriately.

Theo - Why Are Estimations So Hard??? PLANNING TASKS AS AN ENGINEER

Why we estimate?

We do estimates at the epic level for the following reasons.

  • Identify who should do it
  • Identify when it should be done
  • Identify low performers
  • Bring risk to the forefront so that it can be addressed/mitigated
  • Prioritize based one ^
  • Identify how long it will take (this will be wrong, but hopefully taking the following system into account will help make it less wrong)

The Breakdown

Our estimation system is broken down into 3 categories, Complexity, Effort, and Risk.

  • Complexity (1-10) - How "hard" is this thing to do?
  • Effort (1-10) - How much work does it take?
  • Risk (1-10) - What are the chances that Complexity or Effort is off?

Getting Started

When first getting a team started thinking in this way we have found that it is useful to often go down to the story level and document the Complexity, Effort, and Risk as it ends up being a forcing function to think about the complexities and risk. Then go back up to the milestone and produce the milestones Complexity, Effort, and Risk. Then you can look at the stories overall and validate that your estmiate for the milestone makes sense.

Once the devs start to get the feeling for thinking about Complexity, Effort, and Risk this process goes really quickly.

Breaking out Research Tasks

As we go through this process we are often running into Risks and most of the time you need to do some further research to understand and mitigate the risk. This is the perfect time to break those tasks out.

You can also see by doing so how breaking the research task out helps you to think about and adjust the characteristics for the story and its associated research task.


The following are a couple examples from the video referenced above with the addition of the developer days estimates.

Display voice levels in pre-call view

  • Complexity: 4/10
  • Effort: 2/10
  • Risk: 6/10
  • Estimate: 4 dev days

To reduce the risk of this task we could create a research task to figure out one of the bigger pieces of risk. For example.

Identify how to get voice levels from 3p SDK

  • Complexity: 2/10
  • Effort: 2/10
  • Risk: 4/10
  • Estimate: 1 dev day