Design systems have become a standard in the digital industry. Virtually every big player uses one—from Amazon 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., , 2001; , 2019; , 2016; , 2018; , 2019; , n.d.). And yet—as we have experienced in various jobs firsthand—it’s still a common situation that the value of having a design system has to be proven again and again. to Boehm & Basili Klüver Loomer Ray Slack Sparkbox For many features implemented in digital products, a simple is enough to convince management, particularly in e-commerce. “If everyone else is doing it, we can just copy with pride,” is an often-heard statement. But the same standard seems not to apply to design systems. competitive benchmark This is most probably due to the fact that, at least at first, design systems are perceived as a very —the value they’ll 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. abstract investment 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 ( , 2021). We’ve personally done it time and again. Callahan To make this reality more manageable for everyone, based on our experience, we’ve devised a general (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 advice (2021) already provides on how to sell a design system. formula to approximate the return of investment Callahan In the following, we will first give a very brief introduction to design systems. Subsequently, we’ll introduce our formula, elaborate on the assumptions we made, and explain the different parameters you can tweak. We’ll conclude with a specific example of how to apply it. A Very Brief Introduction to Design Systems A design system is a “collection of , guided by clear standards, that can be assembled together to build any number of applications.” ( , 2019). Examples of design systems are by Google, by Salesforce, and by Shopify. Zalando also has a design system, about which they regularly . In general, it is safe to say that design systems have become a staple in every serious digital organization, independent of the kind of industry. reusable components Fanguy Material Design Lightning Polaris write on Medium It is important to note here that design systems should not be confused with mere or simple ( , 2020). A true design system spans the whole organization in terms of interaction and visual design, engineering, , , and so on. It introduces on how and why to use them, particularly in combination, on top of the ‘simple’ components. style guides component libraries Speicher brand design content clear guidelines “A design system [sometimes also called a ‘design language’] 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.” — (2021) Fessenden It allows for 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: creating and replicating design work More quality and consistency (cf. , 2019); Wong 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, he’d 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 ( , 2015). We base this article, and our formula, on the , which means that designers and developers work out “what the system is and spread[ing] it out to everyone else. Without quitting their day jobs on product teams.” (Curtis, 2015) We do this for two reasons. Curtis federated model First, if you have trouble gaining management buy-in in the first place, arguing for a centralized model—with a dedicated team taking care of the design system—might only complicate the mission further. A is a good starting point because designers and developers can simply get working on the design system ‘on the side.’ It can then be transformed into a centralized model—or a hybrid one (cf. , 2018)—once the value of the design system has been recognized. federated approach Manwaring & Mateo Second, in a centralized model, a design system often evolves into a , complete with product managers, customer support, and so on. However, for the sake of keeping our formula as feasible as possible, we’re focusing only on designers and developers in the following. Design system‒induced productivity gains for such teams are easy to benchmark, and you’ll see that just this limited scope already makes for a very compelling case. product of its own The ROI of a Design System Our design system ROI formula has two components: What you’ll over time from the design system you build; gain What building and maintaining will you. cost Having calculated these two components, it’s straightforward to use them in the standard formula to calculate ROI. In the following, we’ll explain all of the different parts in more detail. Assumptions Our formula orients at the ‘ ,’ i.e., at first, you’ll 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. Design System Efficiency Curve For a specific formula, however, it’s 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 ‘good’ for five years (= months). That is, we anticipate a major revamp roughly every five years, e.g., due to a change in brand identity. This is where the in the formula comes from. We’re 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. 60 60 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 the and in the formula could be tweaked accordingly. We consider our assumption reasonable for an ‘average’ set-up with ~10 designers and ~30 developers (plus/minus). 240 120 However, a design system takes at least 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 designers’ or developers’ time in setting up a design system. That’s why we have included the and functions in the formula, and that’s where the and (60 months minus 6 months) come from. 6 max min 6 54 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. That’s why we have instead of in the part of the formula. 3 6 gain After the ramp-up phase, we have full productivity gains. With these assumptions in place, we can now have a look at what the parameters , , and mean. X Y Z Parameters denotes the percentage of time invested in building the design system. If X=20, the formula gives us 240⁄20=12 months of ramp-up phase. X : Note For X<4.62 , the formula “breaks down” since the ramp-up phase would be ≥5 years. 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. Y denotes the amount of time saved by using the design system in percent. This is equal to productivity or efficiency gains. Z and are relatively straightforward to specify: you ‘just’ have to agree on how much time you want to / can spend taking care of the design system. However, is a different story. Since it’s the productivity gain yielded by the design system, it’s impossible to know the parameter precisely beforehand So, how can we estimate in a meaningful way? Essentially, this is a predictive judgment, so we followed the advice by * (2021)—considering the base rate of design system productivity gains by doing a literature review and averaging the numbers reported. X Y Z . Z Kahneman et al. The existing studies about design system productivity gains we found most convincing were (2019), (2016), (2018), (2019), and (n.d.). Klüver Loomer Ray Slack Sparkbox Klüver (2019), Ray (2018), and Slack (2019) Report 50%, 31%, and 34% better efficiency for teams, which means an average of . design Z=38 Klüver (2019), Loomer (2016), and Sparkbox (n.d.) report 25%, 20%, and 47% better efficiency for teams, which means an average of . development Z=31 Hence, in our case, we calculated ROI separately for design and development teams with the two different values for , and then aggregated it afterward. In the next section, we’ll guide you through how exactly that works. Z 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% ( ) of their time during the ramp-up phase and afterward 10% ( ) for maintenance. They moreover rely on the above base rates for productivity gains ( for design, for development). They start with the ROI for the design team over the next five years. X=30 Y=10 Z=38 Z=31 Design On the side, a 30% time investment means the ramp-up phase would be months long. That is, months would be effectively spent on building the design system. Afterward, months remain for the 5-year period, and of those, 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. cost 240/30 = 8 8*30% = 2.4 60-8 = 52 52*10% = 5.2 On the side, a ramp-up phase of 8 months would mean four months of half the productivity gains. That is months. Afterward, for the remaining 52 months, we would see full productivity gains, i.e., months. Overall, the design system would therefore save the design team 20.52 months of needless work. gain 4*(38%/2) = 0.76 52*38% = 19.76 Together with the 7.6 months of work spent on building and maintaining the design system, this yields an ROI of . In other words, you get $2.70 back for every dollar invested in the design system. (20.52-7.6)/7.6 = 170% If one designer costs $5,000 a month, that means the design system would cost Acme, Inc. while it would save them when looking at the design team alone. 7.6*$5,000*5 = $190,000 20.52*$5,000*5 = $513,000 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, the 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. cost On the side, however, we have to exchange the value for , from 38 to 31. Luckily, that’s the only thing, and the rest remains as above. gain Z So, in the case of development, we’d invest 7.6 months and save 16.74 months of unnecessary work. This gives us an ROI of . (16.74-7.6)/7.6 = 120% If one developer costs $6,000 a month, that means the design system would cost Acme, Inc. while it would save them a whooping when looking at the development team alone. 7.6*$6,000*10 = $456,000 16.74*$6,000*10 = $1,004,400 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 = (1,517,400–646,000) / 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. We’ve played around with some variance in the parameters (please feel free to do so on your own) and for the final result, ±25% seems to be reasonable. For instance, “we estimate 135% ROI and $900,000 (±225,000) net gains from the design system over five years.” Conclusion Based on Ben Callahan’s ‘Design System Efficiency Curve’ 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 our . design system ROI calculator in Excel 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 ( , 2021). Callahan 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 simplicity—we 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 parameter . (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.) Z Despite all these limitations in our approach, the value of a design system is undeniable. We’re 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, it’s 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. ☕ I love coffee, and if you enjoy what I write, you can if you like, or subscribe to . 🗞️ spend me one my newsletter 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. “ .” 34, no. 1 (2001): 135–137. Top 10 list [software development] Computer Callahan, Ben. “ .” A List Apart, February 9, 2021. Accessed July 28, 2022. The Never-Ending Job of Selling Design Systems Curtis, Nathan. “ .” EightShapes, September 17, 2015. Accessed August 4, 2022. Team Models for Scaling a Design System Fanguy, Will. “ .” Inside Design Blog, June 24, 2019. Accessed July 28, 2022. A Comprehensive Guide to Design Systems Fessenden, Therese. “ .” Nielsen Norman Group, April 11, 2021. Accessed July 28, 2022. Design Systems 101 Kahneman, Daniel, Olivier Sibony, and C. R. Sunstein. *. HarperCollins UK, 2021. Noise Klüver, Anja. “ ,” YouTube video, 29:45, November 29, 2019. Design as an Agent for Change: The Business Case for Design Systems Loomer, Drew. “ .” Projekt202, October 13, 2016. Accessed July 28, 2022. How Your Company Benefits by Building a Design System Manwaring, Brendon, and Josh Mateo. “ .” Spotify Design, December 2018. Accessed August 4, 2022. The Paradox of Design Systems Ray, Bryn. “ ” UX Collective, July 19, 2018. Accessed July 28, 2022. How Much Is a Design System Worth? Slack, Clancy. “ .” Figma, December 19, 2019. Accessed July 28, 2022. Measuring the Value of Design Systems Sparkbox. “ .” Sparkbox.com, n.d. Accessed July 28, 2022. The Value of Design Systems Study: Developer Efficiency and Design Consistency Speicher, Maximilian. “ ” The Startup, May 31, 2020. Accessed July 28, 2022. What’s a Design System, Design Language, and Design Language System? And What’s the Difference? Wong, Euphemia. “ .” The Interaction Design Foundation, October 2019. Accessed July 28, 2022. Principle of Consistency and Standards in User Interface Design Co-authored with Guido Baena Wehrmann Copyright © 2022 by & Guido Baena Wehrmann • Originally published by Maximilian Speicher Smashing Magazine