Replication and Validation of a Time-Series Forecasting Model for Process-Control System Efficiency in Ethiopia (2000–2026)

"background": "Time-series forecasting models for industrial process-control efficiency are critical for infrastructure planning in developing economies. A previously proposed model for predicting efficiency gains has been cited widely but lacks independent validation using local operational data. ", "purpose and objectives": "This study aims to replicate and critically evaluate the methodological robustness and predictive accuracy of the specified forecasting model within the context of a developing industrial sector. The objective is to determine its validity for long-term strategic planning. ", "methodology": "We executed a direct computational replication using the original algorithm and specifications. Model performance was then tested against a newly collated, high-resolution dataset of system operational parameters. Forecasting accuracy was assessed via mean absolute percentage error (MAPE) and Diebold-Mariano tests. The core autoregressive integrated moving average model is defined as \ᵈ yt = c + =1^{p\ \ᵈ yt-i + =1^q\ -j + \, where \ᵈ is the differencing operator. ", "findings": "The replication confirmed the model's structural form but revealed a systematic overestimation of efficiency gains by approximately 18% in out-of-sample forecasts. The 95% confidence interval for the key long-term trend parameter was found to be 0. 021, 0. 034, which does not contain the original point estimate of 0. 041, indicating a statistically significant downward revision. ", "conclusion": "The original model provides a useful but optimistic framework; its unadjusted application for capacity planning may lead to substantial overinvestment. The revised parameter estimates suggest a more gradual trajectory for efficiency improvements. ", "recommendations": "Future applications of this model must incorporate recalibrated parameters and regular updating with real-time data. We recommend the model be integrated with supplementary physical degradation models for enhanced fidelity. ", "key words": "process control, forecasting replication, time-series analysis, model validation, industrial efficiency