The main use of simulation software in engineering is to replicate and analyze real-world processes or systems to assess performance and identify potential issues. Engineers use simulations to create virtual models of products, testing them under various conditions without physical prototypes. This approach helps optimize designs, reduce development costs, and forecast how systems will behave in practical applications. By running simulations, engineers can evaluate factors such as stress, fluid dynamics, and thermal performance, leading to better-informed design decisions and improved overall project outcomes.