That's what I like about Germany and German Unions.
If UPS in Germany slows down, the union will and company will agree upon "Kurzarbeit".
Which means insteading of drivers/workers doing OT (UPS policy to make almost every driver to work 10-12 hrs per day).
They will shorten those days by an hour or 2, to keep the others employed.
Even if it's a 40 hr work week, they'll settle for everyone working 35 hrs per week instead (as an example).
And when things pick up, again - they all go back to their full hrs of work. Simple as that.