At manufacturing sites, four trillion and three shifts, which repeat eight hours of work and rest a day, are normally applied.

Recently, the manufacturing site of Korean conglomerates has been shifting to the second shift of 4 trillion won, not the third shift of 4 trillion won by the younger generation's employees.

The second shift of Group 4 is a form of work in which two of the four workers work 12 hours a day, and the other two take a break.

This is a form of work that reflects the MZ generation's demand to work and rest when working, which refers to the generation born in the early 1980s and early 2000s.

POSCO is the first South Korean conglomerate to introduce MZ generation's second shift in Group 4.

POSCO has been piloting the second shift of Group 4 since 2010 and introduced it completely since 2011.

As a result, the closed day of the second shift of Article 4 trillion became the closed day of 191 days, up 88 days from 103 days, the annual closed day of the current 4 trillion 3-shift system.

Following POSCO's Group 4-2 shift, Hyundai Steel is pushing for Group 4-2 shift, while other oil refineries and others are discussing Group 4-2 shift.

There are positive aspects of the MZ Generation's demands for Article 4-2 shift, and the "work-life balance" that seeks balance between life and work rather than money.

However, for employees who work in three shifts of four groups and are familiar with the pattern, 12 hours a day is burdensome among some workers.

In terms of the local economy, there are also voices of concern as workers who worked in three shifts of Article 4 show regional living patterns as the number of holidays increases.

POSCO and other companies that previously conducted Group 4 two shifts were able to improve employees' satisfaction by changing working patterns while minimizing side effects that could occur when switching to Group 4 two shifts with sufficient pilot operation period.

It seems necessary to change the working system that minimizes side effects of workers and the local economy through sufficient discussion and pilot operation by late companies that will apply the second shift of Article 4.