Which man is most closely associated with the use of interchangeable parts on an assembly line?

Eli Whitney is most closely associated with the use of interchangeable parts on an assembly line. He popularized this manufacturing technique in the late 18th century, particularly in the production of muskets for the U.S. government. Whitney's approach allowed for faster assembly and easier repairs, laying the groundwork for modern mass production methods. His innovations significantly influenced manufacturing processes in various industries.