Humans suck at statistics - how agile velocity leads managers astray

Humans are highly optimized for quick decision making. The so-called System 1 that Kahneman refers to in his book "Thinking fast, thinking slow". One specific area of weakness for the average human is understanding statistics. A very simple exercise to review this is the coin-toss simulation.

Humans are highly optimized for quick decision making.

Get two people to run this experiment (or one computer and one person if you are low on humans :). One person throws a coin in the air and notes down the results. For each "heads" the person adds one to the total; for each "tails" the person subtracts one from the total. Then she graphs the total as it evolves with each throw.

The second person simulates the coin-toss by writing down "heads" or "tails" and adding/subtracting to the totals. Leave the room while the two players run their exercise and then come back after they have completed 100 throws.

Look at the graph that each person produced, can you detect which one was created by the real coin, which was "imagined"? Test your knowledge by looking at the graph below (don't peak at the solution at the end of the post). Which of these lines was generated by a human, and which by a pseudo-random process (computer simulation)?

One common characteristic in this exercise is that the real random walk, which was produced by actually throwing a coin in the air, is often more repetitive than the one simulated by the player. For example, the coin may generate a sequence of several consecutive heads or tails throws. No human (except you, after reading this) would do that because it would not "feel" random. We, humans, are bad at creating randomness and understanding the consequences of randomness. This is because we are trained to see meaning and a theory behind everything.

Take the velocity of the team. Did it go up in the latest sprint? Surely they are getting better! Or, it's the new person that joined the team, they are already having an effect! In the worst case, if the velocity goes down in one sprint, we are running around like crazy trying to solve a "problem" that prevented the team from delivering more.

The fact is that a team's velocity is affected by many variables, and its variation is not predictable. However, and this is the most important, velocity will reliably vary over time. Or, in other words, it is predictable that the velocity will vary up and down with time.

The velocity of a team will vary over time, but around a set of values that are the actual "throughput capability" of that team or project. For us as managers it is more important to understand what that throughput capability is, rather than to guess frantically at what might have caused a "dip" or a "peak" in the project's delivery rate.

The velocity of a team will vary over time, but around a set of values that are the actual "throughput capability" of that team or project.

When you look at a graph of a team's velocity don't ask "what made the velocity dip/peak?", ask rather: "based on this data, what is the capability of the team?". This second question will help you understand what your team is capable of delivering over a long period of time and will help you manage the scope and release date for your project.

The important question for your project is not, "how can we improve velocity?" The important question is: "is the velocity of the team reliable?"

Picture credit: John Hammink, follow him on twitter

Solution to the question above: The black line is the one generated by a pseudo-random simulation in a computer. The human generated line is more "regular", because humans expect that random processes "average out". Indeed that's the theory. But not the the reality. Humans are notoriously bad at distinguishing real randomness from what we believe is random, but isn't.

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How injecting randomness into your project can help it succeed

Success and failure differ, very often, by very little. Take nature as an example. A small change in our DNA (a few mutated genes) can have catastrophic consequences. On the other hand, without these mutations humans would never have come into existence.

Humans and other species in the planet evolved because of chance (although not totally chaotic) changes in their DNA. As small change after small change happened, the surviving individuals were able to spread the viable, and ultimately the most adequate changes to the next generation - and the process repeats still in our own bodies today. If Nature has taught us something about improvement and evolution is that you must have a little bit of luck involved!

The DNA of a project

In software projects - my domain - I see some similarities to this natural model that are worth exploring. Projects also have a DNA which includes the structure and the communication connections between individuals. Communication being one of the most quoted causes for failure in software projects, and therefore one of its critical success factors.

The More I Practice the Luckier I Get

Once a project gets started, a particular structure is put in place (governance, management, teams, etc.). Very often that structure remains in place, and static until the end of the project. But is this a smart choice?

Another aspect of the project that rarely changes is the network of connections between the individuals. This network is what carries information from individual to individual and eventually "selects" the information that is acted upon by the project team. If a piece of information reaches an individual in the project, and that individual does not consider it relevant, that information will not spread further. In contrast, when a piece of information is perceived as important by an individual, that information will be actively spread by that individual.

The Illusion of Control

The structure that is set for a project strongly influences the communication links that can emerge between individuals. Who talks to whom? What meetings exist where people interact regularly? etc. But the reverse is also true. The existing communication network within an organization is a strong influence on what governance structure is put in place, how teams are formed, etc. These co-dependent processes create a positive (or negative) spiral of events for the project, but because neither (structure, or communication network) is often changed, that spiral is unstoppable. If it is positive, it will help the project succeed. If this co-dependent processes create, instead a negative spiral, that will relentlessly remove the chances of success for that project.

This co-dependent relation between two key processes (structure and communication network) is why we can increase the chances of success in our projects by simply causing random perturbations in the project. Randomness helps us explore different patterns for structure and communication networks.

As we carefully design and inject small - safe-to-fail - changes into the project, we can observe how it reacts and adjusts. Later, we can retrospectively amplify or remove/dampen the changes based on the outcome we see. If something works, keep it and ask how can you make it grow. If something creates a net negative outcome, dampen or remove it completely.

The cycle goes like this:

• Define and implement small, safe-to-fail changes in the structure or communication network for the project
• These changes lead to emergent behavior as the individuals and teams adapt to the changes
• A new project configuration emerges which drives new project results
• Finally, we evaluate the results of these changes and decide which components we will try to amplify or dampen

What Do You Mean Random?

There are many ways in which we can, randomly, explore better configurations for our projects. Below I list only a few to illustrate the concept:

• At the start of a project, let the teams chose their own composition. This establishes new connections between individuals in the project as some will choose to work with new team members. However, these new connections will not eliminate the previous connections between individuals. The net effect should be that your project now has a more connected communication network (more individuals with strong connections to each other). In practice this works just like when we form new neural connections in our brain: more connections leads to different thinking and acting patterns
• Organize common project events where people interact with each other outside the day-to-day routine. Planning events can be organized following a structured approach, but including also some unstructured time (à lá unconference, using e.g. Open Space) where people can interact based on their interests. This will also help form new connections between individuals in the project and spread information that would otherwise be locked down and not accessible
• Have regular project "coffee breaks" that happen at the same time and same place. In these events people can connect with other individuals and ask questions from the project management team or the most connected individuals in the project. This unstructured communication increases the chance that some piece of information will "jump the hierarchical borders" and reach people in decision-making positions, or people with influence that can later act on that information.

Conclusion

These practices are designed to inject randomness (unplanned situations or connections) into the project. The goal is not to create Chaos (a scary word for many project teams), but to generate new pathways for the information to flow within the project team, as well as novel project structures that are more adapted to the current challenges the teams face.

Using these (or other) practices will increase your project's chances for success. They don't eliminate the need for the project to be managed, or to have structure. They do increase the chance of success for the project by exploring new organizations and structures through a process of small (safe-to-fail) changes that can lead to unplanned, but ultimately superior performance.

These were just a few examples. How would you inject randomness into your project? Have you done that in the past? Please share your experiences in the comments for the benefit of others.

Photo credit: John Hammink, follow him on twitter