Supply Chain Resilience: Evaluating Theory of Constraints and Lean Approaches - a TOC-Based Simulation and Comparative Analysis between the Two Strategies Using anyLogistix

As a consequence of the turbulent economics and socio-politic contexts, the concept of supply chain resilience has gained unprecedented relevance among organizations, currently pursuing management strategies capable of withstanding and quickly recovering from unexpected disruption events. This thesis focuses on two significant paradigms: Lean Management and Theory of Constraints (TOC). Although both strategies are well-established, their contribution to supporting supply chain resilience under perturbative conditions needs further exploration. Moreover, the current literature lacks rigorous, resilience-based comparative analyses between the two strategies, including empirical, simulation-based comparisons. As a result, the thesis addresses the gap by designing a simulation model under TOC principles and by performing discrete-event simulations using anyLogistix. Within the framework of a case study of a firm located in Northern Italy, the TOC-driven model is tested under both normal operating conditions and disruption events. Key resilience indicators selected from the literature reviewed – such as On-Time Delivery, Fulfilment Rate and Time-to-Recovery – are assessed. The same methodological framework applies to a Lean-driven simulation model, which is designed and deeply discussed in the complementary thesis entitled: “Exploring the Effect of Two Strategies on Supply Chain Resilience: Modeling and Simulation of Lean Strategy with Comparative Analysis of Theory of Constraints Using anyLogistix.” The two models are designed in order to ensure a methodologically consistent comparative analysis. Disruptions are simulated in both scenarios following the same methodological criteria and the resilience indicators’ values are systematically collected. Under these conditions, a rigorous, resilience-based evaluation of the simulations results for Lean and TOC strategies is performed. The analysis revealed that supplier-level disruptions represent the most critical vulnerability due to the ripple effect, caused by single sourcing and further amplified by reduced inventories, with Lean exhibiting more severe performance losses than TOC. While Lean is cost-efficient and effective for short-term events, TOC proved significantly more resilient when facing medium- and long-term disruptions, particularly thanks to its strategic logic of buffering and Drum-Buffer-Rope (DBR).