What do engineers know about the actual use of the products they design? What do they know about the customer users’ interaction with products? Are use instructions clear, intuitive and coherent? What about use context: current knowledge of the use environment, user error, space where new products really used, how used? Safety, reliability, ergonomics, efficient use, risks, and more. The speaker will show experiences in learning the elements of the user interface system made Visual: people, tasks, touch, line of sight, equipment, lighting, light, air, air flow, efficiency. This presentation demonstrates visually, conceptually and describes practically the elements of customer use that design engineers need to identify and solve problems, design product functions and thereby differentiate their products that satisfy customers.