Front End Engineering Design Maturity and Investment Decision Quality in Public Infrastructure

Front end engineering design (FEED) establishes the technical and commercial evidence on which capital investment decisions depend, yet its maturity is frequently treated as equivalent to document completion. This state-of-the-art review examines how FEED maturity, accuracy and quality relate to final investment decision (FID) effectiveness and public infrastructure performance, with particular attention to Uganda. A critical narrative synthesis was developed a targeted verification of peer reviewed research, Construction Industry Institute resources and Ugandan public investment sources. The evidence distinguishes deliverable development from confidence in its underlying assumptions, and identifies investment governance as the mechanism through which front end information can influence execution. Industrial project studies associate stronger FEED with improved cost performance, but their observational designs and potentially overlapping samples limit causal and cross sector inference. Infrastructure definition tools, project validation, external benchmarking and sustainability assessment provide complementary decision support. The review identifies unresolved problems in measuring FID effectiveness, transferring industrial instruments to public infrastructure, separating readiness from organizational capacity and assessing long term public value. An integrated framework is proposed that combines sector specific scope definition, independent assurance, stakeholder and safeguard readiness, affordability and documented approval conditions. It treats governance and external uncertainty as contextual influences and includes feedback from operations into future project preparation. The framework is a research proposition rather than an empirically validated Ugandan model. Longitudinal project records and independently verified baselines are needed to test its explanatory value and calibrate approval thresholds.