통상임금 소송에서 신의칙 적용 법리 검토

The good faith principle should be applied even to the labor relation governed by labor laws because it is a continuous relationship that requires trust. The application of the good faith principle for retroactive claims of additional wage arising from an increase in the scope of the ordinary wage in ordinary wage lawsuits should be actively made considering the following. First, the historical authoritative interpretation environment for ordinary wages must be taken into account. Second, the agreement between labor and management should be acknowledged as a decision made by equal partners. Third, the management difficulty should be judged only by the unexpected burden caused by breaking trust. In particular, since collective agreements need to be given a high degree of trust, in the case of agreements under collective agreements, severe managerial difficulties should be considered only to the extend that exert an excessive burden on management.