Value is the Reuleaux triangle of Design Thinking

Richard Simms
Jan 7 · 8 min read

Reuleaux is the triangle formed at the centre of Venn diagrams. The three intersecting circles of desirability, feasibility and viability that forms Design Thinking. Which often refers to Reuleaux triangle as innovation in many models and describes an idea or solution, where value-based design focuses on the value created for organisations and people. It increase your confidence in making the right product decisions, through testing and optimising the return on investment of a vision. So before you write any code or decide on any a feature we need to understand the potential value.

How to test and optimise the ROI of a vision

Today we are all too often feature factories, with little regard for whether the features actually solve the underlying business problems.

A value-based design process can deliver real value to clients. This will help to establish yourself as a trustworthy digital partner. Value-design keeps us focused on outcomes, and forces us to check as we build how our product works and what it accomplishes.

The inconvenient truth about product design, Marty Cagan states that at least half of the ideas are just not going to work. Even when we do find the ideas that are valuable, usable and feasible. It takes many iterations to get the implementation of this idea to the point where it actually delivers the expected customer and business value.

There are many reasons for an idea to not work out. The most common is that the customers aren’t as excited about this idea as we are, so they choose not to use it. When they do want to use it, if it’s so complicated that it’s simply more trouble than it’s worth, this yields the same result. Even when we validate that customers will love it, it can become much more involved to build than we thought. We simply can’t afford the time and money to deliver.

How to change the conversation

Value-based design is to fundamentally change focus from outputs to outcomes. Many of our beliefs about users, their problems, and possible solutions are assumptions that need to be tested. We can do this by building in small, iterative pieces with the goal of learning whether our assumptions are well-founded — and ultimately whether our ideas or features will have the outcomes we want, both for the business and for our end users.

Show stuff to users and experts and get feedback, then make it better based on that feedback.

Always think problem first

  • Always start by taking a fresh look at the problem and discovering why the problem exists

Learn and respond

  • Run a series of experiments in close collaboration with your users

Cross-disciplinary teams

  • Working closely and including the client or the product owner as an active design participant

Build a common language

  • Strive toward shared understanding at all times

Keep experiments light and explicit

  • Move quickly and don’t invest too much in a particular solution

Outcomes, not outputs

  • Focus on the changes in user behaviour you want to see — rather than specific features

A Value-based design process

When building digital tools and services, it’s tempting to think in terms of features. But our users don’t care about what features our products have. They care about what they can accomplish. This is also true of our clients who own their products. While they may talk about features, they actually care more about whether the product helps them achieve their mission and business goals.

Based on consumer insights and learnings, this process can create a product strategy. To define hypotheses about what delights your customers in margin-enhancing ways.

  • Identify and more deeply understand the challenge facing the organisation and its stakeholders

Value-based design keeps us focused on outcomes and forces us to check, as we build, if our product works and what it accomplishes.

Identify assumptions and problems

Solutions are based on a set of assumptions, build a shared vision for your project and start learning about why the problem exists. Value-based design is all about surfacing and testing those assumptions. Before diving into deciding what to test, it’s important to consider all of your project’s potential assumptions, interview stakeholders and subject matter experts. Gather data from analytical tools to understand the business problem. Combine these insights with industry data to frame market opportunities and inform priorities.

  • We believe our users have a need to…

Now that you have answers to all the questions, organise them into groups to make it easier to review them. It’s especially helpful if you can do this activity with your team so you can have more input from everybody.

Conduct discovery research

Create a well articulated understanding of your customers, to build a foundation of knowledge. It’s also the quickest way to improve the quality of your idea or make an informed pivot to an even better idea.

Problem Scenarios & Alternatives

Problem Scenarios are where you identify specific objectives for your product and the steps customers take to achieve their goals. These may be interactions, habits, or desires that you’ll deliver against. They should be real and observable, hence the emphasis on ‘alternatives’. If these problem scenarios exist, the customer is doing something about them now. It’s important you understand those alternatives — your proposition will need to be better.

Gather your research and use it to create a problem statement. Describe ways that you will know (or measure) when you have solved the problem.

We have observed that product / service / organisation isn’t meeting these goals / needs, which is causing this adverse effect. How might we improve so that our product / service / organisation is more successful based on these measurable criteria

Value Propositions, Assumptions & Experiments

The Lean Startup is about identifying your key assumptions. Proving or disproving them as quickly and efficiently as possible. Keeping the venture focused on this in the early days will save you lot of money and grief.

Turn assumptions into hypotheses statements, then prioritise from most important to least important. Then, decide which stories should be moved to the product backlog, and finally which make it into the release backlog.

We believe that creating this experience
For this user / persona
Will result in this outcome
We’ll know we’re right when we see this metric

User stories & Prototypes

Aligning your product development with Personas & Problem scenarios is particularly important. The User Stories make for a great transition point and prototyping will help you think through what you have in mind.

Customer Discovery & Experiments

Successful innovators are constantly learning and constantly testing what works. By measuring the outcome of a hypothesis, you can determine if it succeeds or fails. An experiment can be many things; from interviews, surveys, landing page validation, usability testing, or prototype of the product.

Apply experiments across personas, problem scenarios, propositions, as well as usability. By thinking of your concepts as scientific tests, we create measurable outcomes, that will help you make major decisions about what to build or how to sell it. You will also be able to know when you’re right (or wrong) and stay focused on getting better.

Product & Promotion

When you are ready to scale to production, turning concepts into design systems will enable you to build out the product quickly and improve the consistency of the user experience.

Design isn’t finished when we launch the product — These are some of the most important activities that drive long term value

  • Analytics Reviews after ~3 months

Strive to deliver continuous value

From product conception right through the product life cycle, this is a systematic execution of continuous design and delivery that helps you focus on the right things at the right time.


👋 Nice to meet you. I’m Richard Simms, a Design Lead. Over the last 15 years, I have designed and developed projects in the digital space, pretty much anything that has a screen. I’ve had the pleasure to work with globally respected brands. Designing human-centred services, transforming ideas into digital products and creating unique customer experiences.


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Check out more Value-based design-related content on valuebased.design.


Value-based design

Value-based design

Richard Simms

Written by

Experience designer @_rsimms and on www.rsimms.com

Value-based design

Value-based design

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