Enhancing sustainability in the production of cruise-ship modules through quality monitoring

Constructing cruise-ship hull is long, complex and requires relatively precise metal carpentry, welding and assembly operations. Timely detection and correction of anomalies is vital to the sustainability of the process, in terms of reducing production time and costs. This paper presents a novel statistical quality control (SQC) methodology for monitoring the workshop for the production of so-called "modules" within shipyards, i.e., roughly parallelepiped sub-assemblies of large dimensions (on the order of several tens of meters on each side), obtained through manual carpentry and welding operations. The proposed methodology adopts a standardized p control chart with samples of variable size, incorporating two elements: (i) it accounts for the high level of customization of modules, and (ii) it takes into consideration the measurement uncertainty associated with the large-volume metrology instrument employed for conformity verification (such as a state-of-the-art Leica RTC360 laser scanner), following the ISO 14253-1:2017 standard. A real-world case study at an Italian Fincantieri S.p.A. shipyard demonstrates its practical application.