Several factors influence modified bitumen membranes in asphalt or bitumen modification systems. Key factors include the type and percentage of polymer used (such as SBS or APP), the compatibility of the modifier with the base bitumen, processing temperatures, and the method of incorporation. Additionally, environmental conditions, such as temperature fluctuations and UV exposure, can affect the performance and durability of the modified membranes. Proper formulation and application techniques are crucial for optimal performance.