This paper analyzed the functions of systems (the grievance procedure system, labor-management joint consultation, and the consultation window to the personnel department) that process complaints and requests from the micro viewpoint of an employee’s voice. An employee questionnaire was used for this purpose. The following four points have come to light as a result of the analysis.

（1）The installation situation of the grievance procedure system, labor-management joint consultation, and the consultation window to the personnel department was analyzed, and it was checked whether all organizations were mutually correlated. Each system was introduced simultaneously.

（2）The analysis of the relation between the establishment of each organization and their use only checked whether the establishment of the grievance procedure system reduces the use of the consultation window to the personnel department. Therefore, the substitution between each organization was small, and the possibility of carrying out functional specialization according to type of voice was suggested.

（3）It turned out that labor unions insist on the installation of the grievance procedure system, labor-management joint consultation, and the consultation window to the personnel department. However, these labor unions did not facilitate an increase in the use of each system, nor did they take any measures to improve the assessment of validity. Thus, a decrease in complaints and requests after the establishment of these systems will lead to a decrease in the use of each system and an underestimation of the validity of these systems.

（4）Although the place-of-work round-table conference had a positive effect on the use and validity assessment of the labor-management consultation system and the personnel department consultation window, there was no significant influence on the grievance procedure system. The result of this analysis can be interpreted as follows. The place-of-work round-table conference serves to receive a complaint and a request with regard to a place of work, which increases consultation with a labor union or the personnel department. The other complaints that place-of-work round-table conference serves cannot receive are then processed by the grievance procedure system.

This paper showed that although the systems tend to be installed simultaneously, each system has a specialized function. The result of this analysis has important implications for grievance procedure systems with few users. To be sure, there has been minimal establishment of a grievance procedure system. However, this is not because the grievance procedure system does not have a significant role, but it is because there are a few specific problems that can be solved only by a grievance procedure system. Therefore the grievance procedure system can be said to have a small and important role.