Design systems have become a standard in the digital industry. Virtually every big player uses oneāfrom Amazon to Google and Airbnb to Uber. There have been numerous studies and reports on their efficacy in improving productivity, reducing bugs, and improving digital products (e.g.,Ā
For many features implemented in digital products, a simpleĀ competitive benchmarkĀ is enough to convince management, particularly in e-commerce. āIf everyone else is doing it, we can just copy with pride,ā is an often-heard statement. But the same standard seems not to apply to design systems.
This is most probably due to the fact that, at least at first, design systems are perceived as a veryĀ abstract investmentāthe value theyāll ultimately produce is not immediately visible and noticeable. On top, the upfront investment can seem huge to management compared to smaller, more concrete features design and development teams could be working on that produce more graspable value (and technical/design debt) more quickly.
Hence, the necessity to prove the value of a new design system beyond a simple competitive benchmark is a reality everyone who wants to get started with this topic must face, as Ben Callahan has already noted in a previous article on the topic (
To make this reality more manageable for everyone, based on our experience, weāve devised a generalĀ formula to approximate the return of investmentĀ (ROI) of a design system with a minimum of parameters. We see this as a handy complement to the great but a little more strategic adviceĀ
In the following, we will first give a very brief introduction to design systems. Subsequently, weāll introduce our formula, elaborate on the assumptions we made, and explain the different parameters you can tweak. Weāll conclude with a specific example of how to apply it.
A Very Brief Introduction to Design Systems
A design system is a ācollection ofĀ reusable components, guided by clear standards, that can be assembled together to build any number of applications.ā (
It is important to note here that design systems should not be confused with mereĀ style guidesĀ or simpleĀ component librariesĀ (
āA design system [sometimes also called a ādesign languageā] is a set of standards to manage design at scale by reducing redundancy while creating a shared language and visual consistency across different pages and channels.ā
ā
It allows forĀ creating and replicating design workĀ quickly and at scale, alleviating strain on design and development resources. It leads to less repetitive work, which enables a focus on larger, more complex problems, more creativity, and more innovation, and therefore has a wide range of advantages:
- More quality and consistency (cf.Ā
Wong , 2019); - Reduced time inefficiency;
- A unified language within and between cross-functional teams;
- Visual consistency across products, channels, and departments;
- An educational tool and reference, e.g., for quicker onboarding;
- A single source of truth for designers, developers, and all other stakeholders.
We believe that if Henry Ford lived today and worked on a digital Model T, heād use a design system.
There are different ways a design system can be built and maintained within an organization, the two most popular ones being the centralized model and the federated model (
First, if you have trouble gaining management buy-in in the first place, arguing for a centralized modelāwith a dedicated team taking care of the design systemāmight only complicate the mission further. AĀ federated approachĀ is a good starting point because designers and developers can simply get working on the design system āon the side.ā It can then be transformed into a centralized modelāor a hybrid one (cf.Ā
Second, in a centralized model, a design system often evolves into aĀ product of its own, complete with product managers, customer support, and so on. However, for the sake of keeping our formula as feasible as possible, weāre focusing only on designers and developers in the following. Design systemāinduced productivity gains for such teams are easy to benchmark, and youāll see that just this limited scope already makes for a very compelling case.
The ROI of a Design System
Our design system ROI formula has two components:
- What youāllĀ gainĀ over time from the design system you build;
- What building and maintaining willĀ costĀ you.
Having calculated these two components, itās straightforward to use them in the standard formula to calculate ROI. In the following, weāll explain all of the different parts in more detail.
Assumptions
Our formula orients at the āDesign System Efficiency Curve,ā i.e., at first, youāll see a drop in productivity due to the necessary upfront investment. Still, after a break-even point where the design system has grown enough to compensate for that, productivity gains are significant.
For a specific formula, however, itās necessary to make some (conservative but adjustable) assumptions. In our case, we have agreed on the general assumptions below in discussions within a design system task force comprising representatives from our design and engineering teams at BestSecret Group.
-
A design system is āgoodā for five years (=Ā
60
Ā months). That is, we anticipate a major revamp roughly every five years, e.g., due to a change in brand identity. This is where theĀ60
Ā in the formula comes from. Weāre well aware that a brand redesign is, of course, no reason to throw away everything and start from scratch again and that a design system might even make a rebrand much easier. However, please bear in mind that we want to make very conservative assumptions here and that if a business decides to shake up things, it would still be necessary to adjust a lot of things in a design system that goes beyond pure day-to-day maintenance. -
The estimate of our designers and engineers was that if one initially invests 20% of their time into building the design system, it will take them 12 months to get it up and running. If they invest less or more, the ramp-up phase will become longer or shorter in a linear manner because a given design system will always need the same amount of effort put into it. Please note that this assumption varies with the amount of person-power a company could put into a design system. Obviously, if there are 200 designers and 200 developers who could all spend 20% of their time on a design system, things might move much faster than 12 months, and theĀ
240
Ā andĀ120
Ā in the formula could be tweaked accordingly. We consider our assumption reasonable for an āaverageā set-up with ~10 designers and ~30 developers (plus/minus). -
However, a design system takes at leastĀ
6
Ā months to set up. Anything less would be unrealistic in a real-world setting (due to coordination and alignment efforts), and we anticipated that probably no business would agree to invest more than 40% of designersā or developersā time in setting up a design system. Thatās why we have included theĀ maxĀ andĀ minĀ functions in the formula, and thatās where theĀ6
Ā andĀ54
Ā (60 months minus 6 months) come from. -
For the first half of the ramp-up phase, we have no productivity gains yet.
-
For the second half of the ramp-up phase, we have 50% productivity gains. Thatās why we haveĀ
3
Ā instead ofĀ6
Ā in theĀ gainĀ part of the formula. -
After the ramp-up phase, we have full productivity gains.
With these assumptions in place, we can now have a look at what the parametersĀ X
,Ā Y
, andĀ Z
Ā mean.
Parameters
X
Ā denotes the percentage of time invested in building the design system. If X=20, the formula gives us 240ā20=12 months of ramp-up phase.
Note:Ā ForĀ X<4.62
, the formula ābreaks downā since the ramp-up phase would be ā„5 years.
Y
Ā denotes the percentage of time invested in ongoing maintenance after the ramp-up phase. In our specific case, we assumed 0.5X, but essentially, Y could be anything.
Z
Ā denotes the amount of time saved by using the design system in percent. This is equal to productivity or efficiency gains.
X
Ā andĀ Y
Ā are relatively straightforward to specify: you ājustā have to agree on how much time you want to / can spend taking care of the design system. However,Ā Z
Ā is a different story. Since itās the productivity gain yielded by the design system, itās impossible to know the parameter precisely beforehand. So, how can we estimateĀ Z
Ā in a meaningful way? Essentially, this is a predictive judgment, so we followed the advice by Kahneman et al.* (2021)āconsidering the base rate of design system productivity gains by doing a literature review and averaging the numbers reported.
The existing studies about design system productivity gains we found most convincing wereĀ
KlĆ¼ver (2019), Ray (2018), and Slack (2019) Report 50%, 31%, and 34% better efficiency forĀ designĀ teams, which means an average ofĀ Z=38
.
KlĆ¼ver (2019), Loomer (2016), and Sparkbox (n.d.) report 25%, 20%, and 47% better efficiency forĀ developmentĀ teams, which means an average ofĀ Z=31
.
Hence, in our case, we calculated ROI separately for design and development teams with the two different values forĀ Z
, and then aggregated it afterward. In the next section, weāll guide you through how exactly that works.
Example
Acme, Inc. has a team of 5 designers and a team of 10 developers who want to kick off building a design system together. They want to prove that the gains yielded by a design system in the mid-to-long term far exceed the necessary investment. Therefore, they grab the design system ROI formula and get going.
They estimate that everyone would probably be able to invest 30% (X=30
) of their time during the ramp-up phase and afterward 10% (Y=10
) for maintenance. They moreover rely on the above base rates for productivity gains (Z=38
Ā for design,Ā Z=31
Ā for development). They start with the ROI for the design team over the next five years.
Design
On theĀ costĀ side, a 30% time investment means the ramp-up phase would beĀ 240/30 = 8
Ā months long. That is,Ā 8*30% = 2.4
Ā months would be effectively spent on building the design system. Afterward,Ā 60-8 = 52
Ā months remain for the 5-year period, and of those,Ā 52*10% = 5.2
Ā months would be effectively spent on maintenance. Overall, there would be 7.6 months (out of five years) of work put into the design system.
On theĀ gainĀ side, a ramp-up phase of 8 months would mean four months of half the productivity gains. That isĀ 4*(38%/2) = 0.76
Ā months. Afterward, for the remaining 52 months, we would see full productivity gains, i.e.,Ā 52*38% = 19.76
Ā months. Overall, the design system would therefore save the design team 20.52 months of needless work.
Together with the 7.6 months of work spent on building and maintaining the design system, this yields an ROI ofĀ (20.52-7.6)/7.6 = 170%
. In other words, you get $2.70 back for every dollar invested in the design system.
If one designer costs $5,000 a month, that means the design system would cost Acme, Inc.Ā 7.6*$5,000*5 = $190,000
Ā while it would save themĀ 20.52*$5,000*5 = $513,000
Ā when looking at the design team alone.
Development
Doing the same thing for development is relatively straightforward based on the above. Since the designers and developers at Acme, Inc. agreed on everyone investing 30% for ramp-up and 10% for maintenance, theĀ costĀ side stays exactly the same. Like the designers, the developers will be busy with the design system for effectively 7.6 months over five years.
On theĀ gainĀ side, however, we have to exchange the value forĀ Z
, from 38 to 31. Luckily, thatās the only thing, and the rest remains as above.
So, in the case of development, weād invest 7.6 months and save 16.74 months of unnecessary work. This gives us an ROI ofĀ (16.74-7.6)/7.6 = 120%
.
If one developer costs $6,000 a month, that means the design system would cost Acme, Inc.Ā 7.6*$6,000*10 = $456,000
Ā while it would save them a whoopingĀ 16.74*$6,000*10 = $1,004,400
Ā when looking at the development team alone.
Bringing It All Together
Combining the calculations for design and development, therefore, yields the following:
-
Design:
- costs = $190,000
- gains = $513,000
- ROI = 170%
-
Development:
- costs = $456,000
- gains = $1,004,400
- ROI = 120%
-
Total:
- costs = $646,000
- gains = $1,517,400 (net gains = $871,400)
- ROI = (1,517,400ā646,000) / 646,000 = 135%
To top things off and make them look more like an approximation, you can round the final numbers and indicate the error. Weāve played around with some variance in the parameters (please feel free to do so on your own) and for the final result, Ā±25% seems to be reasonable.
For instance, āwe estimate 135% ROI and $900,000 (Ā±225,000) net gains from the design system over five years.ā
Conclusion
Based on Ben Callahanās āDesign System Efficiency Curveā and our own experiences with pitching design systems to management, we have devised a general formula with only three parameters for quickly and easily calculating the ROI of a design system. We hope this formula will prove useful to our many colleagues that are just as excited about design systems as we are and want to get started working on this. As a little additional helper, you can download ourĀ
We know all of this is just an approximation based on a lot of assumptions. Additionally, we have only considered designers and developers in a federated model here, and not dived deeper into topics like onboarding benefits, scale benefits, consistency and trust benefits, and better accessibility and usability, which all provide value on top of plainly being more productive (
Also, we have not considered productivity gains for the product, QA, and user research teams and so on (who as well benefit from a design system) in our formula. One reason for this is simplicityāwe wanted to provide a formula that is feasible and easily understandable. Another is that efficiency gains in design and development teams are at the core of a design system, and benchmarks are widely available for determining the parameterĀ Z
. (All this, however, also means that the true ROI of a design system is probably much higher than what our formula yields, which makes the case even stronger rather than weaker.)
Despite all these limitations in our approach, the value of a design system is undeniable. Weāre confident that our formula can reliably prove this and help build a compelling case, at the very least, for cases similar to ours. Otherwise, the underlying assumptions can be easily fine-tuned. And if in doubt, itās always possible to implement a design system MVP and prove its value through a controlled experiment. We just hope we can help you get that MVP approved.
ā I love coffee, and if you enjoy what I write, you canĀ
Acknowledgments
We want to thank Ben Callahan and Martin Schmitz for taking the time to read earlier drafts of this article and providing invaluable feedback. And, of course, a big shout-out to all members of the BestSecret Design System Task Force.
References
- Boehm, Barry, and Victor R. Basili. ā
Top 10 list [software development] .āĀ ComputerĀ 34, no. 1 (2001): 135ā137. - Callahan, Ben. ā
The Never-Ending Job of Selling Design Systems .ā A List Apart, February 9, 2021. Accessed July 28, 2022. - Curtis, Nathan. ā
Team Models for Scaling a Design System .ā EightShapes, September 17, 2015. Accessed August 4, 2022. - Fanguy, Will. ā
A Comprehensive Guide to Design Systems .ā Inside Design Blog, June 24, 2019. Accessed July 28, 2022. - Fessenden, Therese. ā
Design Systems 101 .ā Nielsen Norman Group, April 11, 2021. Accessed July 28, 2022. - Kahneman, Daniel, Olivier Sibony, and C. R. Sunstein.Ā
Noise *. HarperCollins UK, 2021. - KlĆ¼ver, Anja. ā
Design as an Agent for Change: The Business Case for Design Systems ,ā YouTube video, 29:45, November 29, 2019. - Loomer, Drew. ā
How Your Company Benefits by Building a Design System .ā Projekt202, October 13, 2016. Accessed July 28, 2022. - Manwaring, Brendon, and Josh Mateo. ā
The Paradox of Design Systems .ā Spotify Design, December 2018. Accessed August 4, 2022. - Ray, Bryn. ā
How Much Is a Design System Worth? ā UX Collective, July 19, 2018. Accessed July 28, 2022. - Slack, Clancy. ā
Measuring the Value of Design Systems .ā Figma, December 19, 2019. Accessed July 28, 2022. - Sparkbox. ā
The Value of Design Systems Study: Developer Efficiency and Design Consistency .ā Sparkbox.com, n.d. Accessed July 28, 2022. - Speicher, Maximilian. ā
Whatās a Design System, Design Language, and Design Language System? And Whatās the Difference? ā The Startup, May 31, 2020. Accessed July 28, 2022. - Wong, Euphemia. ā
Principle of Consistency and Standards in User Interface Design .ā The Interaction Design Foundation, October 2019. Accessed July 28, 2022.
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