Monday, August 19, 2013

Forget the long planning sessions and work break down: use Blink estimation

One of the less fun parts of my job is that I spend a lot of time doing estimations. As with all estimates, sometimes they are quiet correct and sometimes they are horribly wrong. Either way it cost us time and money to get some estimates, which in the end are… just estimates.

Most of the time I use a work breakdown to create my estimates. This approach has 3 big disadvantages(in my opinion):

  • It’s very time-consuming
  • It leads to overestimating. Typically the more depth you add to the work breakdown, the higher the estimation will be.
  • It doesn’t allow you to manage uncertainty. In the end you still have to use some gut feeling to apply a factor depending on the level of uncertainty or risk.

Last week I was reading about an alternative approach: Blink estimation.

The idea of Blink estimation is that if you bring the right mix of people with sufficient experience in the room you can reasonably assess how this project is similar to, and different from, previous ones, and how much you should reasonably invest to realize the business impact associated with it. If everyone's gut feeling is that the project can be done in 5 months with 4 people, than chances are that we will indeed succeed in realizing the project in 5 months with 4 people.

There are a small number of “rules” to increase the likelihood of it working. There are three things you need to do blink estimation:

Experts estimating

Blink estimation is a comparison exercise that draws on the context you’ve built up becoming an expert. So you need a context of many previous projects. You need to gather people from different disciplines: testers, analysts, project managers, programmers, architects, operations and support engineers among others. Choose disciplines that are likely to have overlapping but distinct areas of expertise. First discuss the potential risks and pitfalls.When people are moving towards a decision point, everyone to estimate size and duration, and then if there are large variances you can explore the assumptions behind the outliers.

Expert messenger

The expert messenger is about knowing how to frame the output of the exercise so it makes sense to the customer. You need to be comfortable describing how experts rely on instinct and intuition, and defending that as a legitimate basis for estimation

Expert customer

Having an expert customer is probably the hardest part. You need a customer that understands the concept is convinced that it can work. Spend some time and effort into educating your customer or client. Once they are on board with the idea of trusting the delivery team’s experience lots of things become a lot smoother.

Read the full article by Dan North and get inspired!

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