Bruce Vojak returns for a short bonus episode on the Hourglass Model — the descriptive state diagram he and his co-authors built to explain how serial innovators actually move from a customer problem to a launched product. Unlike stage-gate, it is not a linear process. It is a map of the five places successful innovators inevitably visit, in whatever order the work demands.
This is a short bridge episode between Part 1 of the Serial Innovators series and the next episode on navigating the politics of breakthrough innovation. If you are an innovator who has ever wondered whether your nonlinear, looping, two-steps-forward-one-step-back working pattern is a sign that something is wrong with you, this episode answers no — and shows you why.
What is the Hourglass Model?
The Hourglass Model was developed by Bruce Vojak, Ray Price and Abby Griffin from over a decade of interviewing serial innovators inside large mature firms. Crucially, Bruce frames it not as a process but as a state diagram — a term borrowed from computer science. Stage-gate is prescriptive: do step one, then step two, then step three. The Hourglass Model is descriptive: here are the five states a serial innovator inevitably resides in during breakthrough work, and here are the patterns of movement between them.
“It describes the innovators that are most successful. And if you recognise yourself doing this, you’re not as crazy as you might think you are.”
— Bruce Vojak
The five states of the Hourglass Model
1. Upper left — defining (and often redefining) the problem
Serial innovators usually start with a problem they have been assigned. But unlike most colleagues, they will go back and challenge the framing. Bruce’s canonical example is Tom Osborne at Procter & Gamble, who inherited the “diaper paradigm” for feminine hygiene products. Tom redefined the problem from “a product to catch fluid” to “a garment that conforms to the body” — and that single reframe became the innovation behind the billion-dollar Always Ultra brand. Not every project requires this reframe. But the willingness to do it when the data warrants is one of the things that separates a serial innovator from a typical inventor.
2. Upper right — deep understanding
This is where the Hourglass Model quietly contradicts a lot of contemporary innovation orthodoxy. There are no beanbag chairs, no foosball tables, no “just let loose and be free thinkers.” Serial innovators sit in deep, immersive understanding — of the customer, the market, the technology, the financials, the manufacturing constraints, and what the organisation will tolerate at different levels. They collect dots before they connect them. Bruce notes that the serial innovators in his research were practising what we now call empathy and design thinking long before those phrases existed.
3. The middle — the cusp between the fuzzy front end and the stage-gate
Here the innovator drops down to try things. Small studies. Conversations with purchasing agents in customer organisations. Early prototypes in front of real buyers. This is where the iterative testing happens — and where the innovator decides whether to keep refining, drop back to the upper left because the problem itself is wrong, or push down into implementation.
4. Lower left — implementation
The structured product development work that maps onto the stage-gate world. Serial innovators do not abandon the work here. They stay tethered, because handing off completely is how good ideas get corrupted on the way to market.
5. Lower right — influencing the marketplace
The often-overlooked final state. The work of preparing the world to receive the product — distributors, channel partners, regulators, key analysts, lead customers. Not letting go. Influence rather than launch.
Why it’s a state diagram, not a process
Bruce uses the computer-science term deliberately. In a state diagram, you have to visit each state at some point, but order is not fixed. A serial innovator might move from upper left to upper right and back again three times before dropping to the middle. They might be mid-prototype, realise they are solving the wrong problem, and bounce all the way back up to the upper left. The arrows on the diagram suggest the more common flows. They are not a script.
This is also why the model resembles, on close inspection, a human body — or, as Bruce reframes Aidan’s observation more generously, a birthing process. Innovation rarely comes out clean and linear. It comes out the way it comes out.
The line every innovator hitting a wall needs to hear
The most useful thing about the Hourglass Model is what it lets the innovator say to themselves on the bad days. It normalises behaviour that mature organisations often pathologise — the loops, the reframing, the bouncing, the apparent silence of the deep-understanding phase.
“If you’re doing all these things and you continually hit a wall, maybe it is okay to leave. And if you’re not doing these things, maybe you better try them before you say, ‘It’s them, not me.'”
— Bruce Vojak
The model is a mirror as much as it is a map. It gives you a template to ask: am I actually doing this work? Or am I blaming the organisation for failing to ship something I never properly framed, understood or socialised?
About Bruce Vojak
Bruce is co-author of Serial Innovators and Innovation Code, founder of Breakthrough Innovation Advisors, and former Associate Dean for Administration at the University of Illinois College of Engineering. He advises executive teams and boards on how to find, support and unleash serial innovators inside mature firms.
Listen and watch
- 🎧 Apple Podcasts
- 🎧 Spotify
- ▶️ YouTube
- 📨 Thursday Thought on Substack — for a chance to win a copy of Serial Innovators, with thanks to our sponsor Kyndryl
Related episodes
- Serial Innovators with Bruce Vojak (Part 1) — who serial innovators are and the MP5 model
- Navigating the Politics of Breakthrough Innovation with Bruce Vojak (Part 2) — coming next
- Iain McGilchrist on The Master and His Emissary — the left/right brain framework Bruce repeatedly references
- Charles Handy on the Second Curve — the S-curve language that runs through both books
Frequently asked questions
What is the Hourglass Model?
The Hourglass Model is a descriptive state diagram developed by Bruce Vojak, Ray Price and Abby Griffin to explain how serial innovators actually move through breakthrough innovation work inside mature firms. Unlike a stage-gate process, it does not prescribe a fixed sequence. It identifies the five states an innovator inevitably visits — defining the problem, deep understanding, prototyping and iteration, implementation, and influencing the marketplace — and shows that innovators move between them flexibly rather than linearly.
How is the Hourglass Model different from stage-gate?
Stage-gate is prescriptive and linear: it tells you what step to take next. The Hourglass Model is descriptive: it tells you what serial innovators do, in whatever order the work demands. Stage-gate works well for incremental innovation. The Hourglass Model better describes how breakthrough innovation actually happens.
What are the five states in the Hourglass Model?
(1) Defining and often redefining the problem; (2) deep understanding of customer, market, technology, financials, manufacturing and organisation; (3) the middle cusp of prototypes, small-scale trials and customer conversations; (4) implementation; and (5) influencing the marketplace before and after launch.
Who created the Hourglass Model?
The Hourglass Model was developed by Bruce Vojak, Ray Price and Abby Griffin and published in their book Serial Innovators: How Individuals Create and Deliver Breakthrough Innovations in Mature Firms. It emerged from over a decade of interviews with 50+ serial innovators inside large mature companies.
Why is the Hourglass Model “descriptive, not prescriptive”?
Bruce Vojak deliberately frames the Hourglass Model as a state diagram rather than a process. A state diagram captures the places an innovator inevitably visits without dictating the order. This better reflects what actually happens in breakthrough innovation, where innovators routinely loop back to redefine problems, abandon and restart prototypes, and revisit deep understanding mid-implementation.
Full episode transcript
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This short episode was brought to you by Kyndryl and the Kyndryl Institute, where you can find a plethora of brilliant thinkers and speakers who have been on The Innovation Show.