2. Defining the essential and eliminating the superfluous

Before moving on to the design stage, it is crucial to accurately assess needs to avoid unintentionally adding any unnecessary functionality. Around 45% of requested features are never used, and 70% are not essential. (Eco-design for the web: 115 best practices (French)). Defining needs is therefore a crucial stage, and must be done in conjunction with the project's stakeholders.

Eco-design is a comprehensive approach to continuous improvement, with the aim of reducing environmental impacts, in particular through restraint. One of the principal cornerstones of this approach is the functional unit.

The functional unit corresponds to the main purpose of the service, and is often expressed in the form of a specific action. For example: “Buying a concert ticket”, “Watching a 5-minute video from a smartphone with 4G”, “Searching for a phone number”, “Making a 20-minute video call”, “Booking a doctor's appointment from a laptop”, etc.

Questions to be asked

The first need to be assessed is that of the digital service itself:

• Is it necessary to use digital technology for this service?
• Are there other, non-digital solutions to meet this need? (see Dedigitize, rematerialize)

Once this is done we can consider other requirements to be defined:

• What actual needs justify the creation of the service?
• Does the added value of the service justify mobilizing the resources required to create it? Do we create more value than we destroy?
• Is this functionality really necessary? Can we do things differently?
• What would happen if we did not have it?
• What is the lowest number required to meet user needs? Number of results, image resolution, sound quality, video length, etc.

The essential role of user experience (Green UX)

Green UX means focusing on the actual needs and expectations of users, to limit environmental impact. Eco-design means going back to the fundamental principles of user-centered design, sometimes misused for commercial purposes (see the section on the risk of greenwashing and persuasive design).

Focusing on the must-haves does not mean sacrificing the user experience - quite the contrary. An example of this is the difference between Google's simple search engine layout (a logo and a search box), as opposed to Yahoo's which is loaded with superfluous information (weather, stock market, news, horoscopes, ads, etc.). (Eco-design: 115 best practices (French))

Not to mention the number of server requests when a search query is run, these two extreme examples meet the same requirement for a search engine, i.e. the functional unit “Searching the web”, but with two completely different UX approaches. The first approach is the most effective in terms of needs, but also the most appreciated by users. Other search engines such as Qwant or DuckDuckGo, more respectful of privacy than Google, also apply this principle of simplicity.

Moreover, applying a “Green-UX” approach has consequences for the entire digital service creation process:

• interface layout decisions,
• selection of components and functionalities,
• the navigation sequence.

This automatically impacts the design, development, maintenance and upkeep of the service. It is therefore essential to think in terms of sobriety and efficiency, with users as our focus, in order to reduce the service's final environmental footprint.