Which aspect does 'design for testing' primarily improve?

'Design for testing' primarily focuses on enhancing the reliability of a product and reducing the chances of failure throughout its lifecycle. By incorporating testing considerations into the design phase, engineers can develop products that are easier to evaluate, detect faults, and ensure that they operate effectively. This approach allows for early identification of potential design flaws or weaknesses, which leads to a more robust final product.

The emphasis on reliability ensures that products meet or exceed performance standards and customer expectations, ultimately fostering trust in the brand and the product's reliability over time. While other aspects such as aesthetic quality, customer satisfaction, and marketing may play roles in the overall success of the product, they are not the primary focus of 'design for testing.' Instead, the primary aim is to create a product that is dependable and minimizes the likelihood of failure, thereby enhancing overall product quality.