Which stage of a product life cycle is not affected by a change in material?

The raw material stage of a product life cycle is primarily concerned with the sourcing and extraction of the basic components that will be transformed into a final product. Changes in material at this stage would directly impact what materials are available for manufacturing, as well as potentially affect the characteristics and environmental impacts of the product. Thus, it is indeed a stage where changes in material have significant implications.

In contrast, the manufacturing stage is influenced by the materials used, as different materials can require different processing techniques, energy inputs, and can affect product quality and performance. Similarly, the usage stage is impacted because the type of material used can determine how effective or efficient a product is during its operational lifetime, as well as its maintenance and required energy consumption. Finally, the end-of-life stage is also affected since different materials can lead to various disposal, recycling, or recovery options, influencing how a product is eventually handled after its useful life.

Consequently, the assertion that the raw material stage is not affected by a change in materials is incorrect, as it is in fact profoundly influenced by such changes, making this understanding critical in evaluating all stages of a product's life cycle.