Requirements is the first phase in software development process that should be taken into consideration, which is a milestone to achieve software success and quality, the difficulty in requirements is requirements changeability, which is hard to control by following the services and functions. Meanwhile, it is important to pin down a set of formal customer requirements, which points out Correctness and Completeness, addressing them through customer satisfaction that revolves around precise services requests, to be conveyed to deep Completeness, through Consistency. Mentioning that Correctness and Completeness point at Quality, while enhancing the Requirements Specification increases its quality, which in turn reflects positively on the product quality. This research addresses the problem of achieving Correctness, Completeness and Consistency in Requirements Specification through UML use case diagram. Applying an automated approach and a (VBA/MS excel) programmed tool based on standard rules to evaluate the approach. The evaluation is established using two standard use case diagrams from the UML site, resulted in improving the Correctness and Completeness criteria in Requirements Specification, and so the quality. Keywords: Correctness, Completeness, Consistency, Quality-based requirements, Use case diagram, Requirements Specification.