Enterprise resource planning (ERP) evolved from materials requirements planning (MRP) software, which was created in the 1960s for large companies who needed to manage complex manufacturing operations. MRP was used mainly to identify, allocate, and track resources such as raw materials, parts, ingredients, and labor. As technology became more accessible, vendors added features for back office (accounting and HR) and front office (sales and CRM). While initially, only enterprises could afford to invest in ERP, it is now more affordable and widely used by small and medium-sized businesses.