The Right Medical Device Starts with a House of Quality Matrix

 In Design Strategy, Medical Product Design

When medical device companies start planning a new device, they often jump ahead and begin with the bells and whistles. They spec out flashy new features and plan out unexpected ways to execute elements that are ordinarily mundane. In doing so, these companies put the cart before the horse

To illustrate how wrongheaded this approach is, consider this analogy. Let’s say you’re building a house. You haven’t yet considered your family’s housing needs, put together a realistic budget, selected a set of plans, or pulled any permits. In fact, you haven’t even identified a lot on which to build. Yet you are already shopping for appliances, window treatments and light fixtures.

Sounds pretty ridiculous, doesn’t it?

Just like the early planning stages of a house-building project, laying the foundation for a medical device isn’t the sexiest part of the process. But it’s absolutely critical if you want to create a successful product. In the world of medical devices, that means thinking carefully about your users’ needs, business goals, regulatory requirements, competitive landscape, and so on. Having the right process to guide you is critical.

And the best way to start is with a House of Quality matrix.

What is House of Quality? How Does it Relate to Medical Device Development?

So what is House of Quality, exactly? It’s a tool that helps product development teams keep their users’ needs top of mind as they lay the foundation for a new product.

House of Quality was first developed by Mitsubishi in 1972. It flowed out of a broader product development method called Quality Function Deployment (QFD), which rose to prominence in Japan in the 1960s. Toyota quickly adopted the tool, and they are now the company most frequently associated with House of Quality. However, they are far from being alone. Today, House of Quality is used widely by manufacturers and product developers across multiple industries.

When product development teams follow the House of Quality process, they identify user needs and correlate them with specific design inputs. They then use a weighting system to appropriately prioritize design inputs and product features based on their relative importance to users.

House of Quality takes the following factors into consideration:

  • Voice of business (VOB), including budget and timing requirements

  • Voice of customer (VOC)

  • Regulatory requirements

  • Quality requirements

  • Marketing needs

  • Competitive analysis

  • Internal product development needs

  • Technical requirements and engineering specifications

The resulting matrix, which is shaped roughly like a house, documents and visualizes these key factors — and the correlations between them. It gives teams a holistic picture of the various factors driving the creation of a new product. And it also guides them in balancing those differing needs appropriately.

Just as importantly, the process of completing the House of Quality matrix brings teams into alignment about a product’s features (and how they should be prioritized) at the outset of the development process. Because of that, House of Quality is really more than just a tool. It’s a vehicle for cross-functional communication and alignment that lays the foundation for a successful project.

Building a House of Quality to Support Your Medical Device

In addition to looking like a house, the House of Quality matrix consists of a set of elements — foundation, walls, ceiling, roof — that correlate to the parts of a house. As with building a house, you start the matrix at the foundation and work your way up to the roof. The parts of the House of Quality matrix are as follows:

  • Foundation. The foundation of a House of Quality matrix begins with a design-engineering survey of similar products already available on the market. As you review the existing comparable products, ask yourself what makes a successful product. From this survey, your team should develop a set of technical, usability, and aesthetic benchmarks for your own product. This portion of the matrix is mostly in your R&D team’s court. However, you should plan to involve your product design team, too.

  • Left Wall. One of the walls in your House of Quality matrix will include your voice of customer (VOC) and voice of business (VOB) requirements. VOC requirements refer to your customers’ needs and preferences related to your product. For example, if you are producing a wearable device, your VOC requirements will likely dictate that your device must be comfortable, aesthetically appealing, inconspicuous, lightweight, and ergonomic. VOB requirements include details like pricing targets, revenue goals, and other business needs driving the product’s development. Each VOC and VOB requirement should be ranked and weighted in order of priority.  This is very important, down the road, if compromise needs to be made to balance feature-time development.

  • Right Wall. The right wall consists of a competitive product analysis. In this phase of the House of Quality matrix, you should list your key competitor products and break out the key features that differentiate them from the pack. Next, you would weight and rank each of these attributes in order of importance.

  • Ceiling. The ceiling of the house consists of all of your product’s technical needs, which come out of bench-marking. This should include regulatory requirements, quality needs, internal product development needs (such as routing times), and technical strength requirements.

  • Roof. The roof of the house, which is shaped like a triangle, is a matrix of all the weights you’ve assigned to the various requirements identified in the foundation, walls, and ceiling. This allows you to look at the full set of requirements holistically and quickly visualize where each of the requirements fit in terms of their relative importance to the end product. It also allows you easily identify lower-priority items in the event that you need to prune features over the course of the development process.

By creating a House of Quality matrix at the beginning of the medical device development process, you bring your entire team into alignment. Everyone, including your marketing, quality assurance, regulatory, manufacturing, R&D, design, and product engineering teams, gets the opportunity to put their needs into the matrix. And then, as a group, you agree on how to prioritize among them.

Not only does this help ensure you put your product on the right path from the very beginning, but it also makes things much easier down the line. Hard decisions often arise over the course of the product development process. With a House of Quality matrix in hand, your team will be able to make quick, informed decisions to keep your medical device headed in the right direction.


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