Reassessing Risk Integration in Investment Appraisal: A Comparative Evaluation of Traditional and Simplified Analytical Models

Abstract

This study provides a systematic examination and critical evaluation of prevailing methodologies for incorporating risk into investment appraisal and project planning. It advances the argument that inadequate recognition or improper integration of risk—often arising from the use of flawed or overly complex analytical models—can materially distort decision outcomes and undermine project viability. Using a desk research approach, the study analyzes cash flow estimates from five projects drawn from the authors’ tutorial archive. The project parameters were assessed using discounted cash flow (DCF) techniques and risk metrics generated through Monte Carlo simulation, Mean Relative Regression (MRR) analysis, and Enyi’s simplified statistical risk model, which also produced the distribution of risk around mean cash flows. The findings reveal that the more sophisticated models not only pose practical challenges in application but also yield inconsistent results. In contrast, the risk distribution insights produced by Enyi’s simplified statistical model offer clearer, more coherent guidance for investment planning and project appraisal decision makers. The study contributes to the literature by highlighting the value of simplified, transparent risk integration frameworks in enhancing the reliability of capital investment decisions.