Interaction Conception for Human Machine Interfaces

This article presents the method I’ve developed as student of L’École de Design Nantes Atlantique (France) and student consultant (then intern) for PSA Peugeot Citroën.

Observation. Collaboration. Prototypes. Iteration.

// repeat as long as the user tests aren’t satisfying.


Constraints / Requirements / Define Users / Values / Objectives / Planning

During the kickoff meeting of the project, my team and I receive as much informations as possible and take in consideration every aspect the project may include, focusing mainly on the constraints and requirements.

I identify the targeted users and the objectives of the experience. In another hand, I take in consideration the values the project should communicate through every step of the experience.

“ Stay hungry ”

Through this first stage I need to understand every aspect of the project to be able to put myself as the first user, the average one and as a refractory user in order to put the experience at its maximum quality requirements.

An overview of the planning is also needed in order to put a scale on the project and then being able to prioritize the right elements.


Benchmark / Intelligence Gathering

After the first stage kickoff, we need to observe the existing projects about identical services or interactions. Looking into any other area is really necessary to be the most impartial possible.

“ Stay foolish ”

For HMIs, inspiration and benchmarks can come from digital environments (websites, apps, in-car infotainment and dashboards…), everyday’s life machine interactions (home appliances, home automation, parking ticket machines, public transportations…) and also from specialized areas of machine interactions (airplane and helicopter cockpits, military aircraft, hospital environments…). Science fiction and industrial innovative concepts remain a big part of inspiration and influence the decisions we can make even if being consistent, realistic and alert is important to focus on the main needs and solve the most important problems the users can face.

Collecting intelligence has indeed an important role and can be enhanced by comparing different points of views, cultures and age groups from within the team or gathered by external sources.


Comparing / Empathy Map

At this stage, it is possible to analyze pain points of similar HMIs and build the empathy map to understand the users in a more pragmatic and consistent way.

Using tools coming from sociology and psychology areas can provide deeper and stronger inputs in order to perceive what would help users to reach the main objectives of the interactions.

“ Identifying the emotional drives is key of building a journey map that fits the needs and motivate the users. ”


Workshops / Brainstorming

Combining different specializations and skills of job positions is relevant to get different point of views and help to get a big picture of every aspects the projects will embrace. It is then important to set up a workshop that mixes different kind of profiles from different departments (engineering, marketing, psychology and sociology, ergonomics, development…). The purpose of this workshop is to bring every ideas that would come up without any constraints in order to get the ideal suggestions.

“ Accept any unusual suggestion ”

Ideas that come out from the workshop need to be processed and synthesized in order to build a structured mindmap of the main functions we would provide through the HMIs, taking in account feasibility of each one of them. Prioritizing can then be realized considering the human, time and budget resources of the department. It is important to stay focused on the main objectives we want to accomplish through the solution we’re developing.


User Journey / Customer Map / Functional Requirements / Prioritization

Once gathering all the informations from the ideation and prioritization of the functions we want to provide to the users, putting all those items into a realistic scale will make the whole project take a major step. Using personas will provide a solid basics for this transformation and support the re-dimensioning. It is important to put yourself in the place of the user, to feel what he would experience at every step of the interactions.

“ From the scenarios, building the user journey with the major interaction steps is critical to identify the smoothness of the experience and the friction points he could face. ”

Writing up a functional requirements report will provide advanced ideas for the production specifications and help the communication with the engineers and developers to build a consistent product in time. Their feedback will serve the prioritization that will lead the achievability of the product.


Early Wireframes / Features Shapes

When we have cleared every aspect of the product we aimed to build, the next step is to draft earliest wireframes we can. Establishing the aspects the functionalities will serve the user enables us to decide how he will interact with them. Focusing on the main features we prioritized will allow us to build fast sketches in order to iterate in an agile way after every user tests rounds.

“ Fast iterations for an agile design method ”


Prototype as a Medium of Discussion

Building an early version of the prototype using the wireframes assets will turn the next team meeting into a brainstorming and decision-making phase around the features we want to bring to the fore by focusing on the consistency and the flowability of the user journey.

It is also possible to show many possibilities through different versions leading to different journey flowcharts, in order to represent the different approaches the team could imagine.

A prototype is not the final product. Do not expect it to look like the final product ”

The prototype can be modified accordingly to every feedback we gathered during this meeting and the issues we identified in the user experience interaction flow.


Verbatim Feedback / Quality Tests / Flow Issues / Pain Points

By collaborating with the ergonomics team, we can write up a brief focusing on the main objectives the user tests will lead to.

“ What do we want to prove, to identify and to analyze from those user tests ? ”

Identifying the user journey’s issues is the main point of this step. It will enable us to iterate in a pragmatic way as many times as the ressources can afford us to and as long as the user tests are not satisfying.


Agile Process Runs

Iteration is the main value of the agile process many industries adopted lately. It is important to analyze every step of it and collaborate as much as possible with other departments to lead us to an efficient final iteration.

“ The iteration process strengthens our commitment and repels us from the apprehension of making mistakes. ”


Clear Details / Communication

Once the final iteration has been validated by satisfying user tests results, it is time to write out every interaction specifications by considering every engineering, development and strategic aspects.

This design brief will provide every department that is involved in the building of the product sufficient informations to consider the user journey we designed.


With this method, the objective is to build a product that answers in the best way the users needs. Through the main steps of the project it is important to permanently focus on the values that will impact the easiness of use without requiring the user to adapt his behavior to the product.

“ The pleasure to use results from this whole process and maintains adoption from users. ”

Approaching the problem from the user perspective defines the quality of the experience we provide through the product we build.


About the author

I’m Martin Baudin, HMI Designer validating my Master Degree (in 09/2017) in Tangible Interfaces at L’École de Design de Nantes Atlantique. I’m focused on designing user flow solutions involving interactions for complex functions.

As an adaptative, quick learner and initiative-taker creative, I’m open for opportunities involving user interactions with any kind of product.