What aspect of job analysis involves defining the essential functions of a job?

The aspect of job analysis that involves defining the essential functions of a job is job specification. Job specification focuses on detailing the qualifications, skills, competencies, and essential duties required to perform a job effectively. This process helps in clarifying what is necessary for the job, including the knowledge, abilities, and other attributes that candidates need to possess. In doing so, it serves as a guide for selecting, training, and evaluating employees.

By contrast, job design determines how tasks and responsibilities are organized within a job, job evaluation assesses the value of a job in relation to other jobs within an organization to ensure equitable compensation, and job classification involves grouping jobs into categories based on shared characteristics or functions. Each of these areas contributes to the overall understanding of roles in a workplace, but defining essential functions is specifically the realm of job specification.