How can such installation errors arise?

Engineer Hofmann: "Such errors can occur if the rigger, despite accurate specifications, drill the holes for the supporting attachments too large by not observing the manufacturer's installation instructions. Holes for supporting attachments are drilled to a diameter of 8.2 (max. 8.5 mm). Unfortunately we had a case recently, wherein a customer drilled support holes with a diameter of 9 mm and drilled even larger."
  

What are the consequences of this error? 

Engineer Hofmann: "The building users told us that the handle sets on the door leaves moved back and forth, almost like they were floating."

How did Grundmann Beschlagtechnik respond?   

Engineer Hofmann: "We made a special drilling jig for this purpose. With it, the support holes were drilled on the door to a diameter of 10 mm.

Special spacer sleeves with a diameter 8/10 mm (inside/outside) were made especially for this purpose and fixed on the dismantled fittings with a special adhesive by the customer on site." (See picture 4: left with sleeve, right without sleeve)

What benefits did the customer get from this special solution?      

Engineer Hofmann: "The fittings are now permanently installed and the existing door leaves could still be used despite this gross installation error. No new fittings were necessary and we tried to settle the whole thing as soon as possible."