Rules, standards and regulations have to be observed in every step of the ship design process. Ignoring these constraints in any case leads to higher costs going along with potentially lower product quality. Numerous investigations have shown that product data model correction activities require considerable resources (man-hours and although money = cost) to obtain an acceptable quality level, and in the worst case, a redesign of potentially larger parts of the ship structure has to be performed. Computer-aided design systems offer a large set of functions to define a product data model. However, in the current situation, these tools are not capable to fully ensure the correctness of the product data model while observing the relevant quality criteria which are generally shipyard specific as they are mainly imposed by the production facilities. A quality management system is introduced which is based on the ISO 10303-59 focusing on quality criteria to be applied for an efficient ship structure production process. The functions of the system will be demonstrated on weldability criteria. These criteria demand notches at distinctive constellations of components depending on their function and, for example, minimum distances and angles between structural parts due to welding processes and material requirements. As an additional criterion, sufficient excess material has to be assigned to plate edges functioning as block boundaries to allow for the correction of inaccuracies in the production process at even late stages. The integration of the product data quality management algorithms with the computer-aided design system, in this case AVEVA marine, shows an efficient correction of inapt data as the automatically detected errors can easily be fixed by means of a guided process including the visualization of the structural parts with the help of the computer-aided design system being applied for data modelling.

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For the modeling of the ship structure, computer-aided design systems are generally used. During the different phases of the ship structure modeling and production process, the correctness of the generated product model data has to be continuously preserved. The correct assignment of position numbers to steel parts, e.g., represents a fundamental requirement of the ship structure production management. According to this requirement, a quality criterion can be formulated, that all parts to be manufactured have to have a position number assigned to with the condition that only identical parts should have the same position number. Two parts are generally regarded to be identical when they have the same properties concerning material, thickness, and shape. Shape in this case includes the outer and the inner contours (holes). The current control mechanisms of the correctness of product model data are manual, drawings-based methods. A new approach has been developed to automatically check the identity of the ship structural parts already during the design phase. This mechanism allows the engineers to maintain the quality of the product model data before it will be handed on for further processing. The approach described in this article is based on the Fre´chet distance algorithm, which is generally used to assess how closely two continuously closed curves resemble each other. The results of the steel structural parts shape comparison are presented in a report. This report can be used to check the correctness of the position number assignments and by this contributes to the overall quality assurance mechanism to preserve a high quality of the product model data. Although errors can be avoided, which will otherwise be detected in later process phases, they have to be fixed with significant additional costs.