Extending the purchasing portfolio model with sustainability risk to differentiate procurement strategies: an AHP case study from Moroccan construction sector

Introduction Traditional purchasing portfolio models remain predominantly focused on financial impact and supply risk, thereby neglecting the Triple Bottom Line (TBL) of economic, environmental, and social performance. While prior studies have proposed conceptual extensions of the Kraljic framework to incorporate sustainability, no previous study has simultaneously combined full TBL operationalization, AHP-based criteria weighting, and empirical illustration within an emerging economy construction context. This study addresses this gap by developing a Sustainable Purchasing Portfolio Model that incorporates sustainability risk as a third evaluative dimension alongside strategic impact and supply risk, representing a methodological advance over existing approaches. Methods The framework is applied to an SME eco-construction firm specializing in adobe brick production in Marrakech, Morocco. Using the Analytic Hierarchy Process (AHP), the study weights 21 criteria across three dimensions and applies the judgment of a single domain expert (the firm’s senior purchasing manager) to classify six key raw materials within the portfolio matrix. Results The results reveal differentiated positioning across the portfolio quadrants. Cement, lime, white clay, and molds all emerge as strategic items requiring long-term collaborative partnerships, though with differentiated sustainability profiles: cement and lime carry high sustainability risk due to carbon intensity and oligopolistic supply conditions. In contrast, white clay and molds present comparatively lower sustainability risk despite their high strategic importance. Water is classified as a leverage item, where supply availability allows the firm to exercise bargaining power within a sustainability-oriented sourcing approach. Testing and quality-control materials are positioned as non-critical items that can be managed through administrative compliance mechanisms. Discussion The resulting bubble-matrix visualization simultaneously integrates strategic importance, supply vulnerability, and sustainability exposure. The study demonstrates that sustainability risk does not affect procurement items uniformly, supporting portfolio-specific rather than standardized sustainability strategies aligned with the UN Sustainable Development Goals.