Products are designed to meet a specific human need or want. A product that doesn't satisfy a need or want is not likely to be successful. Products need to research: what consumers want and what they are willing to pay for it. Engineers might have to cut back on different features and options to hold down production costs. If you have researched then you will get investors. Criteria - special requirements a product must have. A constraint is a limit, such as appearance, budget, space, materials, or human capital, in the design process. Constraint could be a manufacturing process that is available, budget, time needed to manufacture the product. Market research will determine, for example, what people would be willing to pay for a new type of phone. The designers might have to cut back on different features and options to hold down production costs.