Stage Gate Decisions Under Uncertainty

Abstract

Megaprojects continue to underperform despite decades of advances in planning, governance, and risk management. At stage-gates, project readiness is typically assessed through the identification and mitigation of discrete risks. While this event-oriented approach is effective for managing identifiable uncertainties, it assumes that relevant uncertainties can be sufficiently articulated at the moment decisions are taken. As a result, forms of uncertainty that are difficult to define - yet critical to project viability - may remain outside formal evaluation.

This research argues that such uncertainty does not primarily reside in isolated events, but in how external developments interact with the dependencies that underpin project viability. Dependencies function as the interface through which external uncertainty connects to the project. When these dependencies are structurally vulnerable and insufficiently stabilised, uncertainty can propagate through the project system before it becomes visible as articulated risk.

Viewing uncertainty through dependencies distinguishes between structural vulnerability and developmental robustness. Vulnerability arises from the position of dependencies within the project configuration. Robustness, in contrast, develops over time as enabling mechanisms stabilise the conditions under which dependencies can function as assumed at the moment of commitment. Project readiness at stage-gates is therefore not determined by the closure of risks alone, but by the extent to which critical dependencies are sufficiently stabilised to carry uncertainty into subsequent stage-gates.

To operationalise this perspective, the research develops the Megaproject Dependency Framework (MDF). This introduces a dependency-based perspective that enables projects to engage with uncertainty before it can be articulated as risk. Starting from the conditions required for project viability, this perspective links external uncertainty to the mechanisms through which the project is configured - such as design choices, sequencing, and contractual arrangements. This makes it possible to identify where uncertainty enters the project, how it may propagate through interdependent elements, and which dependencies are most likely to be affected by changes in the external environment. By combining structural vulnerability with uncertainty propagation, the approach provides a structured basis for identifying where stabilisation is required to support commitment, shifting attention from managing isolated risks to strengthening the conditions under which the project can remain viable.

The framework is applied to two carbon capture and storage megaprojects. The analysis shows that many articulated risks can be traced back to underlying dependencies and their development conditions. High-impact risks are consistently associated with dependencies exhibiting high levels of instability, defined as the combination of structural vulnerability and strong uncertainty propagation. External shocks act as triggers that activate this instability, making previously latent exposure operational.

The findings indicate that risks do not form an independent layer of analysis, but can be interpreted as partial and governance-visible expressions of deeper dependency dynamics - particularly in situations where uncertainty is difficult to articulate in advance. This positions dependency analysis as a precursor to risk articulation, offering a way to engage with uncertainty before it can be meaningfully expressed as discrete events.

This research shows that stage-gates do not eliminate uncertainty, but instead consolidate how exposure is carried forward. Project readiness is therefore best understood as the degree to which dependency instability is sufficiently bounded to support commitment. The MDF provides a complementary analytical lens to existing risk-based approaches, enabling projects to identify where uncertainty is likely to materialise and how it may propagate, without replacing established governance practices.