The EU-funded ASSISTANT project (project no. 101000165) aims to develop breakthrough solutions for the manufacturing industry, using artificial intelligence to optimize production systems. One of the keystones of ASSISTANT is the creation of intelligent digital twins. By combining machine learning, optimization, simulation, and domain models, ASSISTANT develops tools and solutions providing all required information to help production managers design production lines, plan production, and improve machine settings for effective and sustainable decisions that guarantee product quality and safety.