Human Resource Management (HRM) performs numerous activities in organizations including employee recruitment, selection, placement, job analysis, training and development, and labor relations. POSCO (Pohang Steel Company) has concerned with employee management related to job placement and analysis among these activities because of the problems of over-complexity of placement precedures for the variety of recruits, the frequency of selection, a large amount of job descriptions / specifications, and their changes. This study, as a phase of developing the entire HRM systems in the organization, briefly summarizes the preliminary information related and describes an implementation of expert system as a means for effective job placement based on the principle of right-person-in-right-place with identifying aptitudes and personalities of employees. Thus, a new approach for developing a job description/specification using a formal specification language like Z is also proposed. The result of this study will cultivate the performance of personnel, prevent conflicts between labor and management, promote overall productivity of organization, as well as helpfully verify job analysis.