Manufacturing is the process of converting raw materials into finished goods through various production methods. Historically, manufacturing occurred on a small scale through apprenticeships or putting-out systems, but the Industrial Revolution led to large-scale manufacturing using machines powered by steam engines. Major technological developments during this period included advances in textiles, metallurgy, mining, chemicals and other industries. Manufacturing systems can involve discrete, process, repetitive, or assemble-to-order production depending on factors like market demand and complexity of the product.