Project quality and product quality are different things, but they are inextricably linked—or they should be. It is possible for a project to seem successful and deliver the anticipated result, only to find out later the product is not what was expected.
Projects are measured on how well they meet the objectives envisioned by the project sponsor. In other words, did the project deliver the expected results? Sometimes, those results are not achievable within other constraints, such as available money, talent and time.