Purpose: The purpose of this paper is to explore how emergent changes are handled in research and development (R&D) projects. R&D projects business potential lies in their exploration of the unknown; conversely, this makes them uncertain endeavours, prone to emergent changes. Design/methodology/approach: Uses a single-case-study design, based on a projects-as-practice perspective and a soft systems methodology (SSM) analysis, to map how ad hoc R&D teams handle emergent changes, specifically the solution identification and assessment phase and the implementation plan. An R&D project in the power industry, involving over 250 engineers, was analysed. Findings: This paper shows how emergent changes are handled differently from initiated changes during the decision-making phase. The system analysis shows that the most critical factors for managing these changes are: collective reflection between project parties; and including experienced engineers in implementation-plan reviews. Practical implications: The results are of relevance both to R&D managers aiming to improve team performance and to general project management. Informal notions of emergent changes can be formalised in the change request process. Weaknesses in the project team’s organisation are highlighted, and details of how of how to mitigate these are provided. Originality/value: Combines engineering-design and project-management research on emergent changes, adding to the former regarding people–organisational and strategic issues. Furthers understanding of the projects-as-practice approach and emergent change (deviations) handling by ad hoc teams in a project environment. SSM has not previously been used to explore aspects of projects-as-practice, and this is a novel way of adding to the body of knowledge on project praxis and practise.