Designing a product is a highly creative process. A design is born of the designer’s need to create something unique or a market need that drives the creation of something unique. Either way, while the design process is subjective and creative it ultimately has to be very functional as well. The process by which this is ensured is called design verification.
Design verification does not signal the end of the design process. An additional step of ensuring that the design works for what it is intended and does so at a cost and quality that is fine tuned is what design optimization is all about. So making sure a functional design performs well under a specific set of operating conditions having used the right amount of labor and materials in creating the design is optimization.