Why write JD:
Personnel management: it is convenient for employees to understand the required abilities, job responsibilities and measurement standards, so that employees can have a principle to follow. It is convenient for superiors to assess employees. The statement of work is the measure.
Performance appraisal: The statement of work provides rules for performance appraisal.
Recruitment: For example, if you want to recruit a department head, you must first understand what the position requires, write a recruitment application form and let the HR department arrange it. The requirements of these positions can be formulated with reference to job descriptions.
Training: It's easy to know what this position does and the differences between positions when doing training demand survey or training course design.
Human resource planning: HR managers and front-line managers should also use job descriptions when communicating or when planning human resources. So job description is the cornerstone of human resource management.