Job analysis is a systematic approach to collecting information about job tasks, responsibilities, and skills required. It assists HR in determining job necessity, equipment, skills, supervision, conditions, and interactions. Common methods include observation, interviews, questionnaires, diaries, conferences, and critical incident technique. The process involves conducting analyses, gathering employee input, choosing a collection method, drafting descriptions, and obtaining approvals. Job analysis benefits recruitment, selection, appraisal, compensation, and training and development.