Do you know how steering differential works? I didn’t either.

I know very little about cars. My comprehension is mostly restricted to cup holders and infotainment systems.

Recently, however, I watched this fascinating video from 1937, filmed by Chevrolet, that explains how steering differential works. It’s a short, 10-minute video, and it’s definitely worth the time – even if you don’t care that much about car mechanics.

Basics of steering differentials

I will, eventually, make a point with this post. I promise.

First, however, let me briefly explain what problem steering differential solves and why is the invention so important.

How is power transferred to wheels?

A car engine generates power and transfers it to wheels through the transmission and drive shaft. Typically, a car will have one engine and the power needs to be distributed to the two wheels (left and right).

As long as the car is going straight, there are no problems.

What happens when the car turns?

Now, the car that goes only straight is not particularly useful.

Let us imagine that we want to turn right.

The car differential problem
The car differential problem

What we see from the graphic is that, when turning right, the left wheel needs to travel a longer distance than the right wheel. To put it simply, if we are to make a smooth turn – left wheel needs to move faster than the right wheel – because it needs to travel the longer distance in the same amount of time. Should both wheels turn at the same speed one of the two things will happen: Axel will break or car will start jumping.

How have engineers solved the problem?

Enter steering differential.

Wikipedia defines differential like this:

A differential is a gear train with three shafts that has the property that the angular velocity of one shaft is the average of the angular velocities of the others, or a fixed multiple of that average.

Fundamental idea of differential
Fundamental idea of differential

The fundamental idea of a differential is to allow the wheels to move at different velocities. The basic principle here is that we have three spools – one for each wheel, and one connecting them. Now, if one of the wheels is not moving or moving at slower velocity, the connecting spool will start rotating to average out the angular velocities. If this doesn’t make sense, watch the video (I’ve forwarded it to the part that shows this).

Thanks for the lesson, but so what?

In the late 90s, agile movement – and scrum in particular – started to gain popularity in software companies. Waterfall methodology was quickly becoming part of the history.

Scrum brought about quite a few changes, but the most profound one was the concept of a sprint. Work would be planned and executed in sprints – short time periods of only a few weeks.

Wheels went out of sync

Suddenly, software businesses (and aren’t we all a software business today), had different cadences.

I remember back in the day – we even had problems deciding how QA (quality assurance) fits in Scrum. Do they have sprints? Are those same sprints, do they lag behind? Soon after, we had to figure out how product management, marketing, sales, finance fits into this.

For example, does it make sense to come up with an annual marketing plan – if we don’t really know how the product will look like in 4 months? Can we set annual sales targets, without knowing the roadmap for the whole year? How do we budget, when we work in 2-week chunks?

Pendulum swing – the initial reaction

The initial reaction to this new phenomenon was, as it is often the case, overreaction in the different direction. Suddenly, everything was kanban. Everyone was doing their work in Trello.

Agile business

I think that one of the things we got wrong for a long time is that agility does not mean just moving quickly. Again, I’ll turn to Wikipedia for a definition of agility:

Agility or nimbleness is the ability to change the body’s position efficiently, and requires the integration of isolated movement skills using a combination of balance, coordination, speed, reflexes, strength, and endurance

To tie the car analogy with agile business – the point is not to make every part of the business move fast (as opposed to slow). An agile business is the one where different functions (wheels!?) can move at different velocities to ensure an efficient change of direction.

If we think of the business strategy as the engine power, we need a system that can ensure that all different parts of the organization work cohesively together – not necessarily in the same way – but work towards a common objective. In a word, Agile business needs a differential.

OKRs, the differential of the agile business

Different people will emphasize different benefits of OKRs, however, at Gtmhub we believe that OKRs ultimately allow organizations to align their strategy with execution. OKRs, as a methodology, sit between strategy and execution – between engine and wheels. They don’t prescribe how a person or team should go about their daily tasks – we typically say that OKR is a link between the goal and effort.

It is not necessary for sales, marketing, and product team to be forced into a single project to get something done. As long as everyone knows what is the overarching objective, everyone can choose their own method and velocity.

Agility is not velocity.