Assumption mapping for product design: how to become more strategic

Let’s say you want to make improvements to your product. And you want your customers to love it. But how do you get there?

You have a talented team (or you are a super talent yourself), brilliant ideas and a clear vision. Shouldn’t be that hard, right?

Yes, talent is important for good design. But product design differs from art: good product design is not about you, it’s about your customers. They are the jury. They need to love your brilliant solutions — because they are the ones who are using them. And all your customers care about is themselves. For them, a good design makes their life easier, takes away “a pain”, and is enjoyable.

Good design is problem-solving.

How well do you know the problem that you are trying to solve with your design idea?

We are actually pretty good at convincing ourselves about how brilliant we are and how much we know. You may not be as certain as you think you are about the problem, and this is where assumption mapping can help.

What is assumption mapping?

Assumption mapping is… well, a map. With this map, you prioritize your assumptions based on impact and uncertainty. First, list out your assumptions about what the user wants, what you can technically do, and what your business goals are. Then, prioritize them on two axes:

  • Knowledge (certain vs uncertain)
  • Impact (low vs high)
Assumption Map - Basic grid

Focus on your riskiest and most unknown assumptions and validate them with further research.

Why is it relevant?

By mapping out assumptions, you can improve your product design decision-making.

  • You can diagnose “gut feelings” and distinguish them from facts to make more data-driven design decisions
  • You can give your research activities a clear focus
  • You can get more buy-in from leadership by tying your product decisions back to impact

The aim of assumption mapping is not to eradicate all uncertainties entirely. If we knew everything as designers, where would there be room for creativity and innovation?

Assumption mapping is a tool that helps us to stay focused during the product design process. It also helps us keep asking questions and stay curious.

How does it work?

Okay, you’re ready to invite your product design team to an assumption mapping session now that you know its benefits. Where do you start?

Here is an outline of the steps you need to take: Before — During — After.


BEFORE: Plan & Prepare

Workshop steps: Prepare a workshop

? Identify your participants

Start with your project goal in mind and list people who could contribute unique expertise related to that topic. Involve a diverse group of people in product design for unique perspectives.

  • Customer needs (call center, data analyst, sales, marketing, user research)
  • Business (business analyst, CFO, trend analyst)
  • Technology (CTO, lead developer)

You are aiming for a mix of 6–9 participants. This range balances variety and reasonable duration for the workshop.

⏰ Schedule the workshop

Though similar to a brainstorm, an assumption map requires additional elements for maximum productivity. Plan some time for steps like:

  • Introduction (get everybody aligned on the purpose of the workshop + the overall project goal)
  • Background information (if you have collected any information already, plan in time to share existing knowledge)
  • Assumption collection (work with prompts or use several rounds of collecting ideas to ensure you get the most variety; depending on the size of your group, you might also want to work in smaller groups, which requires additional time to share ideas with the large group)
  • Prioritization (expect discussions about the relevance of each assumption)
  • Wrap up & next steps (plan in some time to align on actionable insights you can end the workshop with)

Depending on the size and the diversity of your team, aim for a 2–4 hour workshop.

✉️ Send out an agenda

When you invite your participants, you want to set the right expectations. In your invite, include:

  • Purpose of the workshop (what we want to accomplish)
  • Reason/ importance of their participation (here is why I need you)
  • Agenda items
  • What to prepare (if anything)

Explaining the workshop’s purpose and activities will help your participants understand their role and find a backup plan if they can’t come.


DURING: Running the workshop

Workshop steps: During the workshop

The workshop should entail 4 core steps:

? Introduction (15–30 minutes)

  • Introduce the project goal and how the assumption mapping exercise ties into it
  • Review the workshop agenda and intended outcome.p
  • Do a round of introduction of each participant (role & expertise as it relates to the project)

? Background information (15–30 minutes)

  • Most projects start with some history. Share a summary of any relevant information for a better understanding of the project and goals..
  • If you have done any user research or collected data, this is also the time to share existing insights and facts to bring everyone to the same knowledge level.

?️ Assumption collection (30–60 minutes)

Now we are taking action by collecting assumptions. Depending on the size of your group and their roles, you could handle this through:

  • Individual brainstorming: Everyone writes their thoughts before sharing them with the team.
  • Group brainstorming: Everyone can share their idea while you/ the facilitator is capturing visibly for the entire team.
  • Small group brainstorming: You split the group into smaller groups, and they brainstorm before they share their ideas with the larger team.

The type of assumptions you collect must be specific to your project and its goals. To get a range of ideas, ask some questions to get the ball rolling. Concentrates on these areas:

Customer needs (Desirability)

  • Who is our target audience?
  • What are they trying to achieve?
  • What do they currently struggle with?
  • How do they currently solve their struggles?
  • What do they want to see improved?
  • How will we create value for them?
  • How does our solution fit into their lives? When and how would they use our solution?
  • What features are important to our audience?

Business needs (Viability)

  • Who do we think are first customers vs followers?
  • How do we think we will generate revenue?
  • How do we think we will attract customers?
  • How do we think we will solve our customer’s struggles?
  • What do we think will make customers come back to us/ become repeat customers?
  • Who do we believe are our primary competitors?
  • How do we think we differ from our competitors?

Technology (Feasibility)

  • What are our biggest engineering challenges?
  • What are legal risks?
  • What are internal governance or policy hurdles?
  • What budget do we have/ where does the budget come from?
  • What time constraints do we have?

? Prioritize the assumptions (30–60 min)

Plot the assumptions across two axes:

  • High risk/ low risk → How bad would it be if we were wrong about this?
  • Known/ Unknown → How much understanding do we currently have?

Your assumptions will end up in one of the four quadrants:

  • High risk, known: Make a plan to overcome the risk
  • Low risk, known: Defer but monitor if risk increases
  • Low risk, unknown: Evaluate your knowledge. What you find out may increase the perceived risk.
  • High risk, unknown: Investigate immediately
Assumption Map Example

?Create hypothesis (30–45 min)

Turn these assumptions into measurable hypotheses (if you haven’t done this already). You want to focus especially on your “high risks, unknowns” for further research.

✅ End with action items

Conclude your workshop by generating a list of actionable next steps.

  • Examine your “High risk, known”. Assign someone to create a plan to overcome these issues.
  • Find someone who monitors the “low-risk, known” items
  • Create tasks to investigate your “high risks, knowns”
  • Decide if there are any actions to take on “low risk, unknown”

AFTER: Engagement through Updates

Workshop steps: After the workshop

Immediately after the workshop, you want to send out:

  • A list with action items, deadlines & the responsible role
  • Any artifacts from the workshop (screenshot/ link to the Miro board, photos of the whiteboard)

If required, share any work in progress along the way to keep up the team engagement.

When should I do an assumption map?

Assumption maps are helpful in guiding your decision-making process and identifying any knowledge gaps. They are most useful at the beginning of a project. We can use them for different objectives:

  • Creating a product roadmap or prioritizing what features to implement (user needs, business impact, tech)
  • Collecting customer data and deciding what type of research you need or what questions to ask (user needs, business considerations)
  • Preparing a usability test and deciding what to focus on (user needs & tech)

Over to you

Where do you see opportunities to start with collecting assumptions? Who should you talk to to collect more knowledge? What are important unknowns you need to uncover?