"background": "Process-control systems in critical infrastructure are increasingly vulnerable to operational and cyber-physical threats. In the Kenyan context, there is a documented lack of longitudinal, quantitative assessments of risk mitigation strategies for such engineered systems, hindering evidence-based investment and policy. ", "purpose and objectives": "This case study aims to methodologically evaluate process-control system upgrades and to quantify their efficacy in reducing operational risk. The primary objective is to estimate the causal effect of systematic interventions on a composite risk index using panel-data econometrics. ", "methodology": "A longitudinal case study design was employed, analysing operational data from multiple industrial sites. A two-way fixed effects panel model was specified: Risk{it = \0 + \1 Interventionit + \ + \ +, where \ and \ represent entity and time fixed effects. Inference was based on cluster-robust standard errors to account for heteroskedasticity and serial correlation. ", "findings": "The implementation of enhanced process-control systems was associated with a statistically significant reduction in the composite risk index. The coefficient \1 was estimated at -0. 18 (95% CI: -0. 24 to -0. 12), indicating an approximate 18% reduction in normalised risk score attributable to the intervention, controlling for unobserved time-invariant site heterogeneity and common temporal shocks. ", "conclusion": "The methodological approach demonstrates that panel-data estimation provides a robust framework for isolating the impact of engineering interventions on operational risk. The results confirm that targeted upgrades to process-control systems can yield substantial and measurable risk reduction in the studied context. ", "recommendations": "Infrastructure operators should adopt similar panel-data evaluation methodologies for capital project justification. Policymakers are advised to develop standards mandating longitudinal risk performance reporting to inform sector-wide resilience strategies. ", "key words": "process-control systems, risk reduction, panel data, fixed effects model, infrastructure resilience
Mwangi et al. (Wed,) studied this question.