Aha, that's new to me....I need to tell that the Grandpas, Pa's and sons of one familiy working at Ineos in Germany, some of them right of the beginning in the 1950ties until their retirement, where whole generations found their work for decades. And a.f.a.i.k. the major projects in the largest Ineos site in Cologne, like the recent new build gas, steam and power plant was planned by internal staff and external engineering companies, than build by externals (quite normal) and than staffed and run by existing Ineos staff again....
Maybe that is due to the fact these people are very deep into "their" plant. Know every screw and pipe and valve and build up a lot of special knowledge and experience, so are not exchanges so easily.....and that these people live close to the plant (what the chemical company prefers and partly requires) and do not move around in Germany from plant to plant. They build their house, get friends, kids are send to school.....and settle down...
I saw that kind of working at BP, where all staff where external people hired for internal projects and when these were finished they were send away to the next project somewhere in the world. Maybe that is an US way to work, but not a European one.
AWo