Customer Spotlight7 min read

Prototyping Smart Home Solutions: A Miele Case Study

Discover how Miele uses ProtoPie to prototype and innovate smart home solutions.

Iulia Sorodoc
Iulia Sorodoc, Product Marketing ManagerJune 26, 2024
Miele oven application created with ProtoPie

Prototyping is essential for IoT innovation, especially in smart home solutions. It allows teams to quickly test and refine ideas, ensuring that devices like smart thermostats, lights, kitchen appliances, and security systems work together seamlessly. By turning concepts into reality, prototyping drives successful IoT innovation.

This blog article focuses on how high-fidelity prototyping propels innovation at Miele. In a recent livestream, Isabel Pfab, Creative Technologist and UX Designer at Miele, shared insights into their design process, highlighting the vital role of ProtoPie in their workflow. Continue reading to discover more about their innovative approach and the impact of ProtoPie on their projects.


  1. What is IoT prototyping?
  2. Six reasons why prototyping is essential for IoT innovation at Miele
  3. How Miele uses ProtoPie in their workflow
  4. Advantages of ProtoPie for IoT innovation
  5. Q&A with Isabel Pfab

What is IoT prototyping?

Prototyping for the Internet of Things (IoT) involves creating early models or versions of IoT devices and systems to test and refine their functionality, design, and user experience. This process includes building prototypes that mimic the behavior and interaction of connected devices, enabling developers and designers to explore ideas, identify issues, and gather user feedback before the final product is developed.

The main goal in prototyping for the Internet of Things is to iterate quickly, validate concepts, and ensure that the final IoT solution meets user needs and functions effectively in real-world scenarios.

Six reasons why prototyping is essential for IoT innovation at Miele

For over 125 years, Miele, a leading German supplier of high-end household appliances, has been renowned for its high-quality products. Offering everything from vacuum cleaners and laundry care solutions to kitchen appliances like ovens and coffee machines, Miele designs its range to transform household tasks into delightful experiences. Discover below six reasons why prototyping is essential for IoT innovation at Miele.

Miele focuses on innovative solutions for household, commercial, and medical technology.
Miele focuses on innovative solutions for household, commercial, and medical technology.

1. Miele's design process is deeply rooted in design thinking

Miele's design process is deeply rooted in design thinking, a methodology that involves understanding the user's problems, defining the scope, ideating solutions, developing concepts, and validating those concepts through iterative testing. Prototyping is integral to each phase of this process, allowing Miele to refine their ideas based on real user feedback.

design thinking at miele
Miele's experience design process is based on the design thinking methodology.

2. Prototyping is essential for physical appliance development

Given that most of Miele's products are physical appliances, they face unique challenges in prototyping. Factors like haptics, sound, and display quality are critical to the user experience and must be tested in realistic settings. This necessity underscores the importance of physical prototyping in Miele's process.

Miele’s signature elements.
Miele’s signature elements.

3. Prototypes vary in levels of fidelity

Prototypes at Miele vary in fidelity from low-fidelity sketches and click-through models to high-fidelity, fully interactive prototypes. These prototypes are essential for early validation, iterative design, and usability testing. Using prototypes, Miele ensures their products meet user needs and expectations before moving into production.

4. Hi-fi prototypes are useful during usability testing

Miele conducts two types of usability testing throughout the product development process: formative and summative usability testing.

Formative usability testing helps refine concepts during development, while summative testing validates the final product. The design team also conducts acceptance testing in collaboration with its market research team to gauge user enthusiasm and willingness to pay for new features.

Prototyping is an essential design practice at Miele.
Prototyping is an essential design practice at Miele.

5. Smart home features require connected prototyping

Miele's smart home features bridge the gap between their digital and physical products, and connected prototyping is essential in their development. Here are three key features:

  1. CookAssist: Guides users to cook the perfect steak using a cooktop and companion app, even without prior experience.
  2. Smart Food ID: Uses a built-in camera to recognize food items like frozen pizza and automatically starts the appropriate cooking program.
  3. Smart Browning Control: This feature allows users to set preferences for cheese browning and crust crispiness. The camera stops the oven once the desired result is achieved.

These features illustrate the importance of connected prototyping with tools like ProtoPie, ensuring seamless functionality and a high-quality user experience.

Smart home features require connected prototyping.
Smart home features require connected prototyping.

6. Prototypes are used for stakeholder communication and idea validation

Prototypes are also used for effective stakeholder communication. Whether convincing project teams, securing budget approval, or presenting to the board of directors, prototypes help convey complex ideas in an understandable and engaging manner.

How Miele uses ProtoPie in their workflow

Before integrating ProtoPie, Miele's prototyping workflow was complex, involving multiple tools and requiring significant programming knowledge. ProtoPie has streamlined this process, enabling designers without extensive engineering backgrounds to create sophisticated prototypes.

ProtoPie simplifies complex product design processes

One notable example of ProtoPie's impact is improving the pairing process for Miele's appliances. Using ProtoPie, Miele conducted numerous usability tests on various pairing methods. For instance, an iPad represented the appliance to test user flows, a mobile phone facilitated the WPS connection method, and a Windows computer acted as a router. In other scenarios, physical prototypes were used, including a versatile prototype designed by a colleague that could switch between representing an oven and a coffee machine.

ProtoPie Connect played a critical role in this experience by simulating real-time device states and communications.

ProtoPie simplifies complex product design processes
ProtoPie simplifies complex product design processes.

ProtoPie bridges the gap for non-technical designers

protopie is entirely no code
One of ProtoPie’s biggest advantages is that it’s entirely code-free.

One of the most significant advantages of ProtoPie is its accessibility to non-technical designers. An intern with no UX or engineering background was able to create a functional click dummy using ProtoPie with minimal guidance.

The app prototype created in ProtoPie demonstrated the complexity of the pairing process. It included various screens, error cases, and technology variations. The ability to reuse and adapt prototypes for different devices and generations streamlined the testing process and ensured consistency across Miele's product range.

A real-world example: appliance pairing

One illustrative example of ProtoPie's use at Miele is improving the appliance pairing process.

Pairing appliances is complex because users can start the process from different points – the appliance, the app, or by scanning a QR code. ProtoPie allowed Miele to prototype these various entry points and interactions, ensuring a seamless and user-friendly experience.

Appliance pairing prototype made with ProtoPie.
Appliance pairing prototype made with ProtoPie.

Advantages of ProtoPie for Internet of Things innovation

Following Isabel's presentation, Collins Che, Business Development Manager at ProtoPie, discussed the benefits of using ProtoPie for IoT prototyping. He emphasized several key points:

  1. Entirely code-free: ProtoPie allows designers to create complex prototypes without writing any code, making the process accessible to those without programming skills.
  2. Custom hardware and software integrations: ProtoPie supports the integration of custom hardware and software, enabling comprehensive testing of IoT solutions.
  3. Usability testing (formative & summative): ProtoPie facilitates both formative and summative usability testing, ensuring that prototypes are user-friendly and meet design requirements.
  4. Early validation of ideas: ProtoPie allows for early validation of design concepts, helping teams to iterate quickly and refine their ideas.
  5. Stakeholder communication: ProtoPie's interactive prototypes are valuable tools for communicating design ideas to stakeholders, making it easier to secure buy-in and support.
Advantages of ProtoPie for IoT innovation.
Advantages of ProtoPie for IoT innovation.

Q&A with Isabel Pfab

The webinar concluded with an engaging Q&A session, where participants asked questions about prototyping for IoT innovation. Here are some highlights:

Q: Why did you pick ProtoPie over other tools?

Isabel: We compared several tools and conducted pilot projects to test them before making a larger commitment. ProtoPie matched most of our prototyping needs, especially for saving time. For all the use cases we identified, ProtoPie proved to be the best tool.

Q: How did you get approval for the budget for ProtoPie? Did upper management understand the value right away?

Isabel: Getting approval right away is never easy. We have a community of practice that helps us decide these things collectively, bringing together colleagues from different departments and countries. Convincing management and IT required demonstrating the value. We logged our time building prototypes with our old toolchain versus ProtoPie and showed how much quicker and cost-effective it was. We also highlighted the enjoyment and efficiency improvements ProtoPie brought, which ultimately convinced them.

Q: Do you also integrate AI into the prototyping to have realistic assistant cases?

Isabel: While I haven't used AI within ProtoPie directly, features like Smart Food ID and Smart Browning Control involve AI. Our AI department handled the computer vision components, and I focused on integrating these into user interfaces to ensure they were understandable and user-friendly.

Q: How did you manage to place cameras inside the oven for the smart browning control

Isabel: It involved a lot of engineering. Finding the right camera technology that could withstand heat and see-through steam was a challenge. We use different cameras in ovens and dishwashers due to varying conditions, but the effort was worth it to ensure the technology works across different platforms.

Q: How do you decide which stage of the product journey requires high-fidelity prototyping?

Isabel: It depends on the hypothesis we want to test or the purpose of the prototype. For stakeholder communication, we need high-fidelity, impressive prototypes. For initial ideas, simple prototypes might suffice, sometimes even paper mockups. It’s about matching the prototype’s fidelity to its purpose.

Q: How do you and your team use ProtoPie to get user feedback?

Isabel: We conduct classical usability tests, mostly qualitative, with around six participants per test day. We present the prototype without much instruction to get genuine user feedback. Prototypes are tailored to specific use cases we want to test, and we develop testing guidelines with experts to ensure we ask the right questions.

Q: Do you use tablets or custom-built devices for testing?

Isabel: We use both, depending on the fidelity needed. For early stages, we use iPads in wooden boxes shaped like appliances to keep the fidelity low. As we progress, we use more realistic prototypes that look and feel like the final product, often with sensors to simulate real interactions.

Q: How accurate are the prototypes you make with ProtoPie compared to the final product

Isabel: At the highest fidelity level, they are very close. The prototypes look and function like the final product, as you would see in the Miele app available in the app store.

Q: Did you also focus on edge cases while pairing?

Isabel: Absolutely. We tested various error scenarios, such as Bluetooth pairing issues when the phone is out of range and other potential problems. This attention to edge cases is why our prototypes have many scenes to cover different possibilities.

Driving IoT innovation with ProtoPie

ProtoPie has significantly improved Miele's prototyping process, making it easier for designers to create, test, and refine interactive prototypes. This has led to better user experiences and more efficient development processes.

By integrating ProtoPie, Miele maintains its tradition of excellence and innovation in household appliances. Join them and begin your prototyping journey today with ProtoPie.