While every project is different there are some ‘truisms’ that can be applied across the board or at the very least to keeping a sense of humour whilst estimating for and engaging in projects. We have created this image of some truisms that have been around for quite a while.

Estimating is what we do when we don’t know

However, it is often the case that we (and management types) expect estimates to have at least an 80/20 degree of positive accuracy. Variations from estimate need to be explained. Smaller variations are easier to dismiss or explain. One of the ‘truisms’ comments on the optimism of software engineers when estimating. They are ‘REALLY optimistic’ when it comes to estimating.

They are not alone.

We are all inclined to be optimistic when estimating the time it will take to perform a task. And lot of this comes down to just humans being human about it.

There’s a great exercise on the Coding Horror blog (extracted from McConnell book ‘Software Estimation: Demystifying the Black Art’) which invites us to estimate to a 90% confidence level a range of things like the surface temperature of the sun and the box office receipts for the movie Titanic.

Think your estimating skills are good? Give it a try here.



How did you go? If you’re anything like me you’re wildly off.

What the exercise reveals is that for the most part humans (myself included) are reluctant to put forward a wide enough estimate to contain an accurate answer, even when in unfamiliar territory.

How funny of us!

Even when we know we don’t know we still tend to put forward a range that is too narrow.

How wide is OK?

It’s not really reasonable to say that a PLM implementation will take between 4 and 100 weeks. As a general rule customers are looking for a greater degree of accuracy than that.

When working on projects in the retail space we are in familiar territory, we can estimate with a much more confident degree of accuracy how long a task is likely to take us. All well and good.

The bit that’s really difficult to estimate is how long it will take the customer. Especially at the beginning of the new relationship.

At the beginning we know nothing about each other. Or as close to nothing as is useful when it comes to estimating time frames. We might know things about how the customer is in other parts of their business and apply these to the project, but this is not a reliable gauge of the time taken.

The thing is that at the beginning we have a set of assumptions, and they are usually positive.

Most of us can improve over time on the estimating game.

But it takes some practice, and familiarity with the subject and people involved. It also takes some effort to truly understand what is in and out of scope.

Most people have their own ‘frame’ through which they see the work they need to get done, consulting and cooperation with team members is key to gaining ownership over estimates.

When we have a lot of uncertainty then the estimation range should be wider if it’s going to include an accurate answer.

The more effort that is put into the planning phase of a project the closer we are likely to be to the estimates.

The key here is to keep estimating and reviewing and reviewing and estimating. As with many things practice makes if not perfect at least a more accurate estimate.

We are all our own unique snowflake when it comes to what is motivating and keeps us on track.

Expectations of project estimates is usually that they will be accurate to an acceptable (i.e. explainable) range. But it’s really difficult to estimate how humans will react to some things… they can get distracted and disillusioned. Especially when the expected time to do something turns out to be wildly inaccurate.

At 6R we are dedicated to working with our customers to create estimates and plans that fit in with the already important business as usual part of work.

As the ‘rules’ or ‘truisms’ say Project management is a full time job, and then some. If you don’t have the capacity or skills in your team we can help with a range of services from supporting and working with internal project management, to project office set up and tools and templates to assist you to get your project over the line.

The original document can be found at Project Connections.com.

6r Estimating Laws