What do 'Performance Specifications' outline?

The correct answer identifies that 'Performance Specifications' outline the minimum system characteristics required for a project. This concept is crucial because these specifications serve as foundational criteria that a system, product, or project must meet to be considered functional and fit for intended use. By defining the minimum acceptable levels for performance, they ensure that all contractors and stakeholders have a clear understanding of the baseline requirements that need to be achieved.

In contrast, while maximum allowed failures might be relevant to quality assurance protocols, it does not capture the essence of performance specifications. Acceptable performance metrics can indeed be part of a broader performance evaluation, but they don't focus specifically on the minimum criteria required for system performance. Lastly, guidelines for user interface design are important but pertain to usability rather than technical performance standards. This distinction helps to clarify the role of performance specifications in planning and executing a successful project.