What aspect should be prioritized when determining the properties of a material for product design?

Prioritizing performance and behavior under specific conditions is crucial in product design because the material must meet the functional requirements of the product. Understanding how a material reacts to various factors—such as temperature, humidity, stress, and wear—is essential for ensuring that the product does not fail in real-world applications.

When materials are chosen based on their performance characteristics, such as strength, flexibility, durability, and resistance to environmental factors, designers can predict how the product will perform over its lifecycle. This consideration leads to the creation of reliable products that meet safety standards and user expectations.

While cost, consumer preferences, and market competition are important factors in the overall design and business strategy, they should not overshadow the necessity of ensuring that the selected material can effectively fulfill the product's intended purpose and withstand the conditions it will face during use. This focus on performance helps to create successful products that meet both design specifications and user satisfaction.