Prioritizing investment strategies for small and medium enterprises: A COWEB-based Pythagorean fuzzy decision-making model grounded in Porter's Five Forces

Small and medium sized enterprises (SMEs) face severe resource constraints, competitive pressure, and uncertainty when selecting investment strategies. Although Porter’s Five Forces provides a strong theoretical basis for analyzing competitive environments, existing studies rarely transform this framework into a quantitative decision support model for SME investment prioritization. In addition, most fuzzy multi criteria decision making studies rely on established weighting techniques and offer limited methodological development for handling complex strategic criteria under uncertainty. To address this gap, this study develops an integrated Pythagorean fuzzy decision-making framework grounded in Porter’s Five Forces. The model evaluates 25 competitive criteria and six alternative investment strategies through expert judgments. Expert importance is determined by a distance based weighting procedure, criterion priorities are calculated through COWEB method, and investment strategies are ranked using COPRAS. The main methodological contribution of the study is the COWEB weighting approach, which forms criterion weights through comparison-based baseline evaluation while reducing assessment burden and preserving consistency. The findings indicate that supply chain stability, switching costs, and customer price sensitivity are the most influential criteria for SME investment decisions. Robustness checks based on comparative ranking, correlation analysis, and sensitivity analysis confirm the stability of the proposed framework. The study contributes to the literature by operationalizing Porter’s Five Forces within a fuzzy quantitative model and provides SME managers with a practical tool for transparent investment strategy selection under competitive uncertainty.