Although a consensus exists on the fact that ergonomists adapt the intervention to each organization’s context, the precise way in which this adaptation is performed and its criteria have been overlooked in the scientific literature. A process evaluation was performed using a multiple case study design, in order to identify context indicators influencing four interventions adopting an activity-oriented approach to ergonomics and performed by ergonomists in training. The evaluation focussed on the steps preceding the implementation of work modifications, namely from request analysis until an action plan was adopted by key stakeholders. Data collection methods included a logbook, progress reports and interviews with ergonomists in training and key stakeholders. Our results presented in logic models show that 12 context indicators were facilitators or obstacles to the progression of the intervention or the action plan. Some combinations of indicators had a positive or negative synergistic effect on the cases. The process evaluation model developed for this interdisciplinary study could be used in future studies to get a better understanding of how the organization’s context influences other kind of ergonomic interventions.