To achieve high quality performance, organizations have to understand and match job requirements and people. This understanding requires job analysis, the process of getting detailed information about jobs. Analyzing and understanding what is required to carry out a job, provide essential knowledge for staffing, training, performance appraisal, and many other HR activities. For instance, a supervisor's evaluation of an employee's work should be based on performance relative to job requirement. In very small organizations, line managers may perform a job analysis, but usually the work is done by a human resource professional. A large company may have a compensation management or total rewards function that includes job analysts. Organizations may also contract with firms that provide this service.