A bill of materials (BOM) lists all raw materials, components, and parts needed to manufacture a product along with their quantities. It defines the product structure by breaking the final product down into subassemblies and components in a hierarchical manner. There are two main types of scheduling: forward scheduling which plans tasks from the start date, and backward scheduling which plans tasks from the due date backwards. Production, planning and control (PPC) aims to efficiently utilize resources through planning and coordinating production activities to transform raw materials into finished goods optimally.