Journal Design Engineering Masthead
African Structural Engineering | 06 January 2019

Methodological Evaluation of Industrial Machinery Fleets in Uganda

A Difference-in-Differences Model for Occupational Risk Reduction
D, a, v, i, d, K, a, t, o, ,, G, r, a, c, e, N, a, k, i, m, e, r, a, ,, A, i, s, h, a, N, a, l, w, a, n, g, a, ,, J, u, l, i, u, s, O, k, e, l, l, o
Difference-in-DifferencesOccupational SafetyFleet ManagementRisk Assessment
Quasi-experimental design isolates causal effect of safety interventions.
Structured inspection programme reduced incident rates by 34%.
Provides a replicable econometric model for fleet risk assessment.
Evidence supports data-driven protocols for industrial regulators.

Abstract

{ "background": "Occupational safety in industrial settings remains a critical challenge in developing economies, with machinery-related incidents contributing significantly to workplace morbidity. Existing risk assessment methodologies often lack robust counterfactual frameworks to evaluate the efficacy of fleet-wide safety interventions.", "purpose and objectives": "This study aimed to develop and apply a quasi-experimental econometric model to quantitatively assess the impact of a structured machinery inspection and maintenance programme on reducing incident rates within industrial fleets.", "methodology": "A difference-in-differences model was employed, analysing panel data from treatment and control groups of industrial machinery units. The core specification is $Y{it} = \\beta0 + \\beta1 \\text{Treat}i + \\beta2 \\text{Post}t + \\delta (\\text{Treat}i \\times \\text{Post}t) + \\epsilon{it}$, where $Y{it}$ is the incident rate. Inference is based on cluster-robust standard errors at the firm level.", "findings": "The intervention yielded a statistically significant reduction in reported incident rates. The estimated average treatment effect was a 34% decrease (95% CI: 22% to 46%) in machinery-related incidents for the treatment group relative to the control cohort following programme implementation.", "conclusion": "The methodological approach provides a rigorous, evidence-based tool for evaluating engineering safety programmes. The results demonstrate that systematic fleet management interventions can substantially mitigate occupational risks in industrial contexts.", "recommendations": "Industrial regulators and firms should adopt structured, data-driven fleet evaluation protocols. Future research should integrate real-time sensor data into the modelling framework to enhance predictive capabilities.", "key words": "difference-in-differences, occupational safety, machinery fleet management, quasi-experimental design, risk assessment", "contribution statement": "This paper presents a novel application of a difference-in-differences model to isolate the causal effect of an engineering safety intervention on industrial machinery incident rates, providing a replicable methodology for the