Towards rigorous problem formulation for engineering design research: from motivations to measurable claims via metric-measure-method

Problem formulation is arguably the most consequential determinant of rigour and originality in engineering design research, yet it remains inconsistently systematized across the literature. Although academic critiques often focus on methods and results, many recurring weaknesses originate upstream, in research questions framed as descriptive prompts rather than operational, analytical engineering problems. This article advances a constructive agenda for strengthening research framing by grounding problem formulation in design–theoretic requirements analysis. Drawing on design theory, requirements engineering, and validity principles, four complementary scaffolds are introduced to operationalise this approach: (i) a taxonomy of common pitfalls to diagnose framing errors early; (ii) a customer–needs–to–functional–requirements analogy for translating broad motivations into operational research requirements; (iii) a Metric-Measure-Method structure to ensure that constructs and evidence are auditable; and (iv) coherence mechanisms that explicitly link research questions to hypotheses, study design, and Type I/II validation. By treating problem formulation as a design artefact, these tools help clarify constructs, surface hidden assumptions, and align methods with specific decision contexts. Ultimately, this framework supports claims that are both falsifiable and transferable, raising the standard of rigour across the field.