HL-LHC naturally inherits procedures and tools developed for the LHC, include an efficient Change Control procedure that provides a smooth and coherent evolution of the “Parameters and Layout” and of the “Hardware Baseline”, which together form the unique and non-ambiguous reference description of the LHC at a given time.
Integrated System Engineering and systematic Technical Reviews, both internal and external, will be enforced whenever strategic decisions must be taken. Both require a complete view of the impact of installing new equipment, important due to the unprecedented complexity of the system and the restricted tunnel space. The integration process proved to be an essential milestone to decide changes in the LHC layout, it provides the necessary inputs for sound scheduling and costing of these changes. HL-LHC benefits from well accepted integration procedures and tools extensively used during LHC preparation, installation and commissioning phases. The process starts with digital models for every component that needs installing in a given area. Storage and change control of all the underlying information and drawings are done with the CERN Engineering & Equipment Data Management System (EDMS) that is systematically used to trace the project baseline evolutions, to follow the procurement and installation of the machine elements (via the Manufacturing and Test Folder – MTF) and to resolve the eventual non-conformities. In addition, to check that the model provides a proper representation of the installed machine, point-clouds from real measurements obtained with a laser scanner can be superimposed onto 3D integration models. These features are important assets when dealing with large system evolution such as the HL-LHC upgrades: a precise knowledge of the environment is essential during the design phase to minimize conflicts between equipment during installation; it allows optimizing the intervention in the field, with a precise identification of the parts that need to be de-installed or modified. Such optimizations are mandatory in activated areas where it must be proven that doses received during any intervention are under control and have been minimized according to the ALARA principle.