Construction is the plant implementation phase, during which all the works and activities planned during the Detailed Design phase are effectively carried out: in this phase, all the major and minor equipment is installed and commissioned to prepare the Plant for Start–up. Before Start-up it is, in fact, necessary to perform a number of preliminary operations, such as checking for proper Construction, the internal cleaning of the equipment and piping, leak tests, instrument calibration, etc., which are increasingly included within the scope of Engineering Companies and viewed as a part of the Mechanical Completion of the Plant. With regard to these activities, GST can assist in both the preparation of the requisite documents for the Tendering Procedures, and the supervision and coordination of Field activities, including the approval of the progress reports by the Subcontractors and auditing the relevant invoices. These services, in the case of small plants can be delivered on the basis of a “Turnkey” type Contract.