Evidence Over Assumptions: The Case for Diagnostic-Led Intervention

Would you start building before surveying the site? Commission architectural design without understanding ground conditions, load-bearing requirements, environmental constraints? The answer seems obvious - of course not. Site investigation precedes design. Evidence informs decisions. Yet when addressing organisational dysfunction in major projects, the pattern reverses: intervention design happens before understanding specific context. Solutions arrive before diagnosis. Assumptions substitute for evidence.

This isn't oversight. It's the industry default. Consultants are brought in, apply a preferred methodology and deploy a standard framework. Alliance mobilisation follows an established process regardless of whether this alliance faces a trust deficit, a capability gap, a structural impediment, or all three. Team building interventions are scheduled without diagnosing whether morale, collaborative capability, or systemic barriers prevent effective teamwork. Culture change programmes are launched without understanding which aspects of current culture enable success versus which aspects create dysfunction.

The diagnostic gap matters because organisations are complex adaptive systems, not mechanical assemblies. What works in one context fails in another not because the intervention was poorly designed but because context differs in ways that matter. Programme governance that enables one client creates bottlenecks for another. Performance management effective in a stable environment creates dysfunction under transformation pressure. Processes supporting established capability become barriers when capability development is required.

Major Projects Association research on mobilisation reveals why assumptions prove inadequate. The research identifies a fundamental gap: mobilisation lacks established industry standards. Their analysis shows "lack of established process for mobilisation across industry" and "inadequate standards for beginning complex projects". The (now superseded by NISTA) Infrastructure and Projects Authority's Project Routemap mentions mobilisation only once - an extraordinary omission given mobilisation determines whether project begins on solid foundation or shaky ground.

When established best practice doesn't exist, diagnosis becomes essential not optional. You cannot apply standard solutions when no standard exists. You won't follow an industry playbook when no playbook has proven substantially effective.  We must understand the specific context: what makes this mobilisation challenging, what capabilities exist versus what are needed, what governance enables versus what does it constrain, what cultural patterns help versus hinder, what systemic barriers prevent collaborative behaviour despite genuine intent.

The diagnostic imperative extends beyond mobilisation to all organisational intervention. The MPA's Project Initiation Handbook emphasises establishing a robust business case and understanding the value proposition. This is a  sund principle, but establishing value requires understanding the current state first - not the assumed state, not a generalised state, the actual state verified through evidence. What collaboration capabilities exist now? What governance creates bottlenecks now? What incentives drive behaviour now? What information flows enable or constrain decision-making now?

The UK Government's Teal Book provides relevant framework for project delivery, emphasising clarity on outcomes, roles, governance. It is valuable guidance. Yet the it assumes diagnostic capability exists to apply frameworks appropriately. Clarity on outcomes requires understanding whether outcome definition is the problem or whether defined outcomes exist but misaligned incentives prevent pursuit. Role clarity requires diagnosing whether role confusion stems from governance design, accountability ambiguity, or capability gaps making specified roles undeliverable.

Consider Alliance formation in infrastructure sectors. Standard mobilisation approaches exist: vision alignment workshop, values articulation, ways of working charter, governance structure design, action planning enabled by professional facilitation. There is genuine engagement and everyone leaves feeling energised. Then the day-to-day operational reality tests unsurfaced assumptions and reveals what wasn't diagnosed. Perhaps trust deficit between parties stems from a previous failed collaboration that workshop activities didn't address. Perhaps capability gaps in constructive conflict management mean disagreements escalate rather than are resolved. Perhaps incentive structures reward individual optimisation despite the "partnering charter". Perhaps information asymmetries create competitive dynamics despite collaborative values.

The diagnostic question isn't whether problems exist - problems always exist when organisations attempt complex delivery. The diagnostic question is which specific problems create dysfunction in this specific context. Generic intervention addresses generic problems. Specific dysfunction requires specific diagnosis enabling targeted intervention.

The diagnostic-led approach makes visible what assumptions obscure. Conversations with people doing the work reveal operational reality beyond formal reporting. Governance observation shows decision-making patterns versus stated procedures. Systems analysis identifies where information flows enable versus constrain collaboration. Behavioural assessment reveals what incentives actually drive choice versus what incentives aspire to drive choice. Integration across multiple data sources creates an evidence foundation for tailored intervention design.

This doesn't mean intervention waits until perfect understanding is achieved. Projects face time pressure and decisions are needed. Action is required. But diagnostic discipline asks: what do we know about why dysfunction exists here specifically, what do we assume, what do we need to verify before committing to intervention approach? Even rapid diagnostics - concentrated effort over days not months - provides evidence foundation making intervention more targeted than the assumption-based deployment of standard methodology.

The organisations achieving genuine transformation through external support recognise diagnostic value. They don't hire consultants to deploy familiar frameworks, they hire consultants to make visible what's invisible internally - patterns people immersed in the system cannot see, assumptions so deeply embedded they're unquestioned and dynamics so normalised they go unnamed. Diagnostic process creates a shared understanding: between client and consultant, across client organisation, among delivery teams. Shared understanding enables targeted intervention addressing specific barriers rather than generic intervention hoping to address unknown dysfunction.

Evidence-based intervention also enables measurement. When diagnosis identifies specific capability gaps, structural impediments, or cultural patterns creating dysfunction, intervention can target those specifically and measurement can assess whether target outcomes are achieved. When intervention is designed on assumptions, measuring success becomes an exercise in sentiment - do people feel better about collaboration? - rather than capability assessment - can people actually collaborate more effectively under pressure?

The measure of diagnostic quality isn't volume of data collected or the elegance of the analytical frameworks employed. The measure is whether diagnosis reveals actionable insights enabling intervention design superior to an assumption-based approach. Does diagnostic process identify specific governance mechanisms creating bottlenecks? Specific incentive misalignments driving competitive behaviour? Specific capability gaps preventing desired collaboration? Specific cultural patterns reinforcing dysfunction despite good intent?

Making diagnosis valuable requires intellectual humility: acknowledging we don't know what creates dysfunction in this specific context until we investigate, resisting the impulse to deploy familiar solutions before understanding unfamiliar problems, and accepting that previous experience informs but doesn't determine current diagnosis. Consultant certainty before diagnosis suggests either remarkable insight or comfortable assumptions. Remarkable insight occasionally exists. Comfortable assumptions more common.

The alternative to diagnostic-led intervention is assumption-led intervention pretending to be diagnostic.  A brief discovery phase is conducted, boxes are ticked, and a familiar methodology is deployed regardless of what discovery revealed. The performance of diagnosis without diagnostic discipline. The appearance of evidence-based intervention whilst maintaining assumption-driven approach.

Genuine diagnostic discipline asks uncomfortable questions. What if our preferred methodology doesn't address the dysfunction we've diagnosed? What if evidence suggests an intervention approach we're unfamiliar with? What if diagnosis reveals problems the client organisation is not ready to address? Diagnostic integrity means following evidence toward conclusions that may challenge consultant expertise, client expectations, or commercial relationships.

The foundation for diagnostic-led consulting is acknowledging complexity. Major projects involve multiple organisations, diverse cultures, competing interests, asymmetric information, ambiguous accountability, incomplete specifications, evolving requirements, external dependencies and political pressures. Assuming a generic solution can address complex specific dysfunctions is hope masquerading as methodology.
What would you need to understand about your specific organisational context to know whether intervention would address the actual dysfunctions?

References

Major Projects Association (2025) Mind the Mobilisation Gap: Why we're still getting mobilisation wrong on major projects, and how we can do better. Authors: Tony Llewellyn and Lisa Martello (ResoLex). February 2025.  Resources available to MPA members only.

Major Projects Association (2017) Project Initiation Handbook: Ten Tenets of Major Project Initiation.  Resources available to MPA members only.

UK Government Project Delivery - The Teal Book