A. The Defendant is the representative director who establishes and operates H (hereinafter “H”) and has been entrusted with the gas safety inspection and autopsy business in Eunpyeong-gu Seoul Metropolitan City by the Seoul Urban Gas Corporation (hereinafter “Seoul Urban Gas Corporation”) from around 2000, and established the said business sector from October 1, 2005 to establish the Seoul Urban Gas I Customer Center (hereinafter “I Customer Center”) and completed a separate business registration, and continued to conduct the said gas safety inspection and autopsy, and then closed the I Customer Center on June 30, 2009.

B. Plaintiff A was employed by Plaintiff B on September 18, 200; Plaintiff C on May 31, 2001; Plaintiff C on March 13, 2002; Plaintiff D on June 25, 2002; Plaintiff E on January 13, 2003; and Plaintiff E on January 13, 2005, engaged in urban gas safety inspection and autopsy. From October 1, 2005, Plaintiff F continued to engage in the same duties at the I Customer Center; Plaintiff F was employed as an employee of the I Customer Center on July 1, 2007, and the Plaintiffs retired on June 30, 2009 as I Customer Center discontinued.

C. From May 2001, H introduced a full-scale annual salary system to the employees. Meanwhile, the Plaintiff A, who was on duty as H’s employee, newly drafted a written employment contract that introduced the annual salary system on March 1, 2001.

(See Eul evidence 14-7). After that, according to the annual salary contract on the one-year basis, all the plaintiffs worked at H or I customer center. According to the employment contract on part of the plaintiffs' work period, according to the employment contract between the plaintiffs and H or the defendant, the amount of monthly basic pay, monthly allowance, the total amount of monthly salary and 12-month salary, and the annual amount of retirement allowance for one-year period are determined, and the amount of monthly wage is determined by 12-month wage. The total amount of the annual salary is determined by 12-month wage.