Points are not Time

By Ben Beckwith on 07 Nov 2016

Somewhere in every process there is a need to discuss the necessary work and the time it takes to do it. It is tempting to estimate a duration for each task, but pointing and measuring can lead to a more flexible estimation process.

I recently completed a cross-country move. To talk about points and time, I'm going to use this move as a metaphor for estimating work.

Pointing the work

Most moving box collections have three different sizes: small, medium, and large. You also have the occasional big-ticket items such as furniture or exercise equipment (in my case a treadmill I didn't want to haul myself).

Points are like the sizes of the items. Is it a small box or a large one? Is it a piece of furniture that will take planning (or disassembly) to get into the house?

Most of the box sizes are the same relative effort to each other. To keep the analogy small, consider only the work of moving a box (ignoring any packing or unpacking). Generalizing the complexity of moving one box from point A to point B is easy. Small boxes are 2 points. Medium boxes are 3 points. Large boxes become 5 points. Furniture items are your 8 pointers.

This metaphor can take many shapes, but for the sake of argument, let us consider the box sizes and the effort to move them. I'm going to leave out packing and unpacking, but you can see how they would add to the effort in moving stuff.

Since we are only considering the size of the boxes, consider the effort to move a particular size. Smaller boxes are easy. Any mover will be able to handle one of these. In fact, some of the movers in my case were able to take two smaller boxes at a time out of the house.

Our medium boxes are larger and a mover will only be able to do one of these at a time. These are still movable by one person, but they take additional care getting through the spaces. Some medium boxes may be so full of heavier items (such as pots and pans) that it requires two people to move without issue.

The larger boxes become tricky because they have one known and one unknown. The known is that is it is a larger shape that will take time to manipulate. The unknown is the weight. Consider a box of pillows compared to a box of tools. Maneuvering a large pillow box by yourself might be possible, but the tools will require additional hands. Some boxes may be so troublesome as to require specialized tools such as a dolly.

Up to this point we have been talking about things shaped like boxes. All of these pack nicely together in a truck. The shapes are largely known and the factors consider for stacking would be fragility and weight. The next items are not as regular as the previous ones.

Our 8 pointers are like furniture. There is no standard shape. You could have a sofa, a bed, a dresser, or a refurbished 1923 Singer Treadle Sewing machine. These are items that do not fit into the regular boxes above. They require much more thought for moving through a given space, and more consideration when packing safely into the truck. It may require several movers to plan and prepare. And it may take more than two to move an item of this size safely. There are many unknowns at this level.

The goal of pointing is to understand the relative complexity of each unit of work. You are establishing the size of the task. You are answering the question, in our example, of how hard it will be to move a given item.

Measuring

The immediate next question is now: given the points, how long does the move take?

The moving companies don't say how long each box takes. There is no chart relating box size to minutes moving. Small boxes do not take 20 minutes. So how do they know how long a move will take?

There is no answer to that until you start to measure your velocity. Points represent the complexity of the work. Velocity is how fast you can get that work done.

As you can imagine, how long it takes depends on your resources and overhead. In our metaphor, the resources are the movers and equipment. The overhead could be the distance to move, or the number of floors to carry the items.

Moving into a house with one mover through one door is different from 6 movers and 8 doors. There may be 20 boxes of work, but the time required will be much different for these two teams.

To get to time, behind the scenes the moving companies have measured the output of their workers. They know a 2-person crew can move 50 points of boxes in four hours. They have done similar work (in complexity or points) to yours and have measured how long it takes.

Keep in mind that you can't always add people to make the work go faster. They will bump into each other in the doors, have to wait longer for the truck, etc. The scaling factor only goes so far before it starts to have more overhead than benefit. Adding people also may add resources to a task. A given truck may fit a crew of 4 nicely, but a crew of 6 will need two.

They can also estimate the drive time between the two places as something separate. In my case, packing up the house onto a truck is the same as any other 3-bedroom house. Moving the truck across country adds days to the overall move.

Points give process flexibility

Points are more flexible than time. When you estimate based on time, you automatically bake in the expected resources and environment. There are no allowances for dynamic changes here. And in doing so, we can't tease apart the true work for each box.

By using points, you can extrapolate time based on your resources and environment. If someone is going to be on vacation, you can make the necessary adjustments to time. You can easily separate out overhead to explain or reduce it. It does not get lost in line-item estimates, but stands alone as its own cost.

Point, Measure, Estimate, Repeat

Moving boxes may be the same, but every move is different. Pointing the work gives you the abstraction to measure the work your team can do. Once you know their abilities, it is easy to estimate and plan. You also have the confidence to identify overhead impacting deadlines.

Done well, this will make you predictable, insightful to the process, and confident. Go forth and point that work!

(Header Image Credit: Chris Tse)

Related Reading

We have other takes on estimating here on the Mutually Human blog. Two related to this are Quantifying Uncertainty In Estimates and Why You Should Do Software Estimates.

A Guide to Estimation and Velocity

If you are feeling the pressure of hitting a deadline or accurately estimating your budget, this free guide can help you.

Get Your Estimation Guide

About Mutually Human

Mutually Human is a custom software design and development consultancy specializing in mobile and web-based products and services. We help our clients design, develop and bring to market innovative products and services based on insightful research and strategy aligned with business objectives. We’ve helped Fortune 500 companies, state governments, and startups.