Several factors influence modified bitumen roofing membranes in asphalt or bitumen modification systems. Key factors include the type and quality of the polymer used for modification (such as APP or SBS), the formulation of the bitumen, the application method, and environmental conditions during installation. Additionally, factors like temperature fluctuations, UV exposure, and mechanical stresses can affect the membrane’s performance and longevity. Proper installation techniques and adherence to manufacturer guidelines are also crucial for optimal results.