What term is used to express the increase in value of a product after each development stage?

The term that best describes the increase in value of a product after each development stage is "Value added." This concept refers to the enhancements or improvements made at each stage of the production or development process, which contribute to a product's overall worth. For instance, when raw materials are processed into components, and then these components are assembled into a finished good, each step adds value due to labor, technology, design, and materials used.

Value added effectively captures the significance of the improvements made during development, showcasing how each phase contributes to the final product's market value. This principle is crucial in manufacturing and service industries, highlighting how businesses can enhance competitiveness and profitability through each stage of the product lifecycle.