Journal Design Engineering Masthead
African Structural Engineering | 13 May 2010

Methodological Evaluation of Process-Control Systems for Yield Improvement in Ghana

A Panel-Data Estimation Case Study
K, w, a, m, e, A, s, a, n, t, e
Process ControlYield ImprovementPanel DataIndustrial Engineering
Fixed-effects model quantifies causal impact of control systems on manufacturing yield.
Analysis shows heterogeneous effects: greater gains in lines with historically higher variability.
Demonstrates value of longitudinal econometric methods for post-implementation engineering evaluation.
Provides evidence-based framework for capital project assessment in industrial settings.

Abstract

{ "background": "Persistent yield inefficiencies in manufacturing and processing sectors present a significant challenge to industrial productivity. The implementation of advanced process-control systems is a proposed solution, but rigorous, longitudinal evaluation of their impact in specific operational contexts is often lacking.", "purpose and objectives": "This case study aims to methodologically evaluate the efficacy of modern process-control systems on yield improvement within an industrial setting. Its objective is to quantify the causal impact of system upgrades using a panel-data econometric framework.", "methodology": "A fixed-effects panel-data model was employed, analysing operational data from multiple production lines before and after the implementation of a distributed control system. The core specification was $Y{it} = \\alphai + \\beta T{it} + \\gamma X{it} + \\epsilon{it}$, where $Y{it}$ is yield for line $i$ at time $t$, $T{it}$ is a treatment dummy, and $X{it}$ are time-varying controls. Inference was based on cluster-robust standard errors.", "findings": "The analysis indicates a statistically significant positive relationship between the control system implementation and yield. The estimated coefficient suggests an average yield improvement of 7.3 percentage points (95% CI: 5.1 to 9.5), holding other factors constant. The effect was heterogeneous, being more pronounced in lines with historically higher variability.", "conclusion": "The application of a panel-data estimation methodology provides robust evidence that targeted process-control system upgrades can substantially enhance manufacturing yield. The case demonstrates the value of causal inference techniques for post-implementation engineering analysis.", "recommendations": "Industrial engineers should adopt longitudinal data collection and panel-data methods for rigorous capital project evaluation. Future system designs should prioritise modules that reduce process variability, as this appears to be a key mechanism for yield gain.", "key words": "process control, yield improvement, panel data, fixed effects, industrial engineering, causal inference", "contribution statement": "This study provides