Project specifications primarily define what a system is expected to achieve rather than focusing only on cost, testing, or technical tolerances. Performance expectations are a critical component because they clearly describe how the system should function under specific conditions, including effectiveness, reliability, and operational outcomes. In Human Resource and organizational management, defining performance expectations ensures that all stakeholders, including employees, contractors, and management, understand the required standards and objectives. This clarity supports accountability, proper training, and effective evaluation of system success. While testing specifications and equipment tolerances are important technical details, they support performance rather than define the overall system purpose. Cost is also a separate consideration. Therefore, option D is correct because performance expectations form the foundation of a well-defined project specification.