Physical boards are great artifacts that go far beyond agile development. They support collaboration, adaptivity and transparency. They're scalable. They engage team members and stakeholders, endure constant experimentation with processes and radiate information about progress. Physical boards are the best natural backdrop for daily stand-ups, discussing problems, handing over stories, picking them up for tests or declaring what's done. Simply said, boards rock.
As one of the Spartez co-founders I can vouch that we've been sold to this idea years ago. This is why we've created Agile Cards: to enable effective and enjoyable work with physical boards for those teams who rely on Atlassian Jira (like ourselves) and - not that long ago - also for those relying on Microsoft TFS or Visual Studio Team Services. And in this new environment a few months ago we got the following review:
This took us by surprise. We've always thought that physical boards were awesome because they work all the time without the need for a power supply. Still, this review inspired me to take a closer look at the environmental impact of Agile Cards due to the paper consumption they rely on.
Are electronic displays really more environmentally friendly than physical boards with paper cards?
To answer this question, I had to do some research. Being an avid hobbyist gardener and a forester, I already had some data and a story to tell.
My first step was to find out how much paper one can manufacture from a single tree. According to various sources (I've looked this up on conservatree.org, paperonweb.com, bizjournals.com and sierraclub.org) this estimate varies from 8 000 to 120 000 sheets per tree, subject to the size, weight, age and species of a tree, as well as the actual manufacturing process. On average, a relatively young (20 - 30 years old) tree can produce about 20 000 sheets of A4 paper, which seems like a fair and quite conservative assumption.
Nowadays most paper gets recycled - thanks to growing ecological awareness, in United States the recycling rate hit its top level of more than 66% in 2015. Knowing this I decided it's safe to assume that one tree, together with the paper recycled from it, can be be transformed into more than 58,000 sheets.
Assuming that a single A4 or letter size sheet can be used to create at least 6 index cards pinned to a physical board, we get over 350,000 index cards from one tree.
Moving forward, I made the assumption that a typical small to medium sized company has 100 employees (that's actually how many of us currently work at Spartez). With such a large group of people tracking their work using boards, let's be greedy with the card use and assume that an average person prints 1,000 cards per year. That adds up to 100,000 index (post-it-note style) cards annually per average company. A few simple math steps later I arrived at an average.
One tree is enough to provide paper for boards in over 3.5 companies for an entire year
Now, let's leverage my foresting passion for a moment. In the last few years near my home, just outside of Gdańsk, I have planted 20 000 trees. Mostly spruce, pine, oak, fir, larch and beech. These trees currently occupy approximately 4 hectares of land which used to be a potato and wheat field. Building on my earlier calculations and entering my 20,000 trees into the equation, I've arrived at an average figure.
20,000 trees can provide paper for physical boards in 3,500 companies (100 employees each ) for 20 years
20 years is also roughly the time when these 20,000 trees could be cut down and new ones planted to produce more paper. This is just theory, of course. I won't cut them. I love my forest.
As for the 3,500 companies, this is still a little bit more than the number of companies which purchased Agile Cards to date.
Moving on to electronic displays, let's take a look at teams which use digital wallboards only. A 60 inch LED TV is a good example of such a display. A modern, energy efficient TV box consumes about 70W of power (e.g. this Samsung UN60EH6000 device). 70W isn't that much, right? Well, with a TV switched on for 10 hours per day and 250 days per year we get:
Bear in mind that this assumption is only valid if the display is really configured to shut down outside of office hours and on weekends. From my experience, this is not usually the case. Let's now assume that our example 100-employee company has 12 pizza-sized agile teams, each team using one electronic wallboard. This amounts to 175 * 12 = 2100 kWh per year. If we multiply this by 20 years and 3,500 companies, we get:
3,500 companies, each using 12 digital boards for 20 years, will consume 148 million kWh
Or 148GWh (giga!). Not peanuts any more.
Now, according to Carbonfund.org, generating 1kWh of electric energy leads to 1.22 pounds of CO2 emission. This is an average for the US, where most of our Agile Cards customers are located.
This means that over 20 years our 3,500 example companies and all their electronic boards will emit:
That's right: 82 thousand tons of carbon dioxide! How many trees would be needed to absorb this?
According to Arbor Environmental Alliance, a single tree can absorb CO2 at a rate of 48 lb. per year. Unfortunately, I was not able to find any reliable source depicting how this number varies across species and age of trees. Assuming that the 48 lb. is an overall tree average, in 20 years time a single tree could absorb 48 * 20 = 960 lb. = 0.43545 metric tons of CO2. So, to absorb all those 82 thousand metric tons of CO2 calculated earlier we need:
188,000 trees would be needed to absorb the CO2 produced by the electric sources powering electronic boards. If these were replaced by paper-based boards, only 20,000 trees would be needed to paper them up.
Even with no recycling at all, paper is far more tree-friendly than an electronic board
And yet we still haven't looked into the environmental impact of energy production. Nowadays, the majority of energy continues to come from "dirty" sources. According to EIA in 2015 in the US 2/3 of electricity was produced by burning non-renewable fuels.
While wood is rarely burned to produce energy at a mass scale, let's take a look how many trees would need to be burned to power the electronic boards at our 3,500 companies.
Wikipedia states that the energy content of wood is 16.2 megajoules per kilogram (4.5 kWh/kg). Tree weight varies widely across species and environmental zones, but for the purpose of this argument let's assume that an average 20-year-old tree can be as heavy as 200 kg. That gives us 4.5kWh/kg * 200 kg/tree = 900kWh/tree of energy generated by burning wood.
To produce the 148GWh necessary to power up boards in 3,500 companies we need:
We'd need to cut down 8 times more trees for producing electricity, than for manufacturing paper to facilitate the same number of boards
Obviously, all of my calculations here are simplified to a large extent. There are tons of other factors and costs related to manufacturing paper, printing cards, developing electronic boards, transmitting and using electric energy. I did my best to make the simplifications on the 'paper' side and on 'electric board' side equal, for the cases to be fairly comparable.
My point here is that electricity does not come for free (yet) and it has a serious ecological toll, far heavier than paper production. With the current average recycling levels, physical boards with paper cards seems to have a 5-10 times lower environmental impact than electronic boards. But even if they were comparable, to me the tangible team interaction against a physical board remains extremely valuable.
Do you agree? Or do you have data which can prove me wrong? Please share your thoughts on this via @ThisIsSpartez on Twitter.