The costs of appeal are assessed against the Intervenor, and the remainder is assessed against the Defendant.

1. Article 2 subparag. 3 of the former Act on the Protection, etc. of Fixed-Term and Part-Time Workers (amended by Act No. 11667, Mar. 22, 2013; hereinafter “fixed-Term Act”) defines discriminatory treatment as “unfavorable treatment in terms of wages, other working conditions, etc. without reasonable grounds.”

The term "cases without reasonable grounds" means cases where there is no need to treat a fixed-term worker differently, or where it is deemed necessary to treat a fixed-term worker differently, the method and degree thereof are inappropriate.

In addition, whether reasonable grounds exist should be determined by comprehensively taking into account the details of the unfavorable treatment in individual cases and the circumstances that the employer considered as grounds for unfavorable treatment, such as the type of employment of fixed-term workers, the content and scope of duties, the responsibility for authority, wage and other working conditions

(See Supreme Court Decision 201Du7045 Decided October 25, 2012, and Supreme Court Decision 2011Du5391 Decided November 27, 2014, etc.). 2. The lower court: (a) determined the basic salary of the comparable workers, who are fixed-term workers, by mixing the annual salary system with the annual salary system; and (b) determined the basic salary system of the Intervenor joining the Intervenor, who is a part-time worker, with the different salary system, based on the degree of difficulty, anticipated work period, worker’s skill in work, authority and responsibility; and (c) accordingly, it is reasonable that the comparable workers were engaged in the same or similar work as the temporary intervenors, and thus, otherwise, remuneration is objectively reasonable for the Plaintiff’s business operation purpose, and the comparative workers, who were engaged in other work, engaged in the same or similar work as the Intervenor.