From use-case to scenario: a proposal for an Ergonomical methodology facilitating an interdisciplinary dialogue in a digital twin design process

According to ISO 23247, a digital twin (DT) is a digital system that monitors a physical entity or product by constantly updating its operational and environmental data. Developing a digital twin requires the mobilization of various digital stakeholders and experts in the field (process engineers, end users, etc.). Interdisciplinary collaboration, with shared common objectives, is crucial to the success of DT design project. However, few methods are currently available to facilitate dialogue. In this article, we propose methodological tools to foster an interdisciplinary design process to develop digital twins that are frugal, accessible, and adapted to future uses. Ergonomics and Human Factor design methods include work and project analysis. Few studies demonstrate how to share the results of these analyses to validate project objectives and scope. The features developed may, as the project progresses, diverge from the initial objectives without being shared and re-examined. It is often recommended to define use cases and scenarios, but these terms don't have the same meaning depending on the designer's profiles. This article aims to provide a shared definition of the terms 'use case', 'Typical Action Situation' (TAS), and 'scenario', and a method for their application. Our method was applied to two digital twin design projects: 1. the TERRA project for traceability in dairy production, and 2. the GEMINI 3D project for prediction, or even correction, of part defects and failures in additive manufacturing. From the beginning of the projects, use cases were used to specify the scope of the DT in its different versions. Then the Typical Action Situations made it possible to define the cooperation between humans and the digital twin (e.g., allocation of functions and transparency in communication between the two partners). Beyond sharing a common definition between users and designers, the methods aim to support a comprehensive change management approach.

Keywords: Ergonomics, Design, Digital Twin, Human-centered Design, interdisciplinarity Use case, Typical Action Situation.