The erection work is preceded by a series of checks at the production facility; and before work starts at site an Operative Safety Plan (POS) is developed. At site, the components ready for erection are positioned on the relevant supports by means of cranes. The various phases of erection are carried out in conformity with the relevant plans, where the exact position for each wood component, for the metal connectors or for the steelwork, is shown. Besides greater speed of erection at site, the high prefabrication level offers many economic advantages. It is also possible to schedule with precision all the work to be done and to coordinate exactly the single skills and personnel present at site.