ClassNK releases Guidelines for 3D Model-Based Approval and related drawing approval system

TOKYO: ClassNK has released the “Guidelines for 3D Model-Based Approval (3DMBA)”, which summarizes the fundamental principles and standard practices for 3DMBA (3D Model-Based Approval), a next-generation design approval approach in which 3D models serve as the primary basis for approval. At the same time, ClassNK has released its 3DMBA-compatible drawing approval system “NK-PASS*¹” and “ClassNK 3DViewer*²,” and has commenced operation of an integrated workflow for 3D model-based design approval.

The guidelines aim to facilitate the smooth execution of approval applications and reviews using 3D models by clarifying the scope of information subject to approval for the handling of design changes, thereby supporting the introduction and operation of 3DMBA, based on a common understanding among shipyards, designers, shipowners, and classification societies. Moreover, the use of the newly released NK-PASS and ClassNK 3D Viewer enables the integrated execution of approval applications and reviews based on Open Class 3D Exchange (OCX)*³. By leveraging 3D models from the early stages of ship design, it is possible to reduce rework and improving the efficiency of design processes.

■ Background

In recent years, the use of 3D models has been expanding in ship design and production. 3D models not only enable the visual understanding of complex structures and arrangements but also facilitate the accurate communication of design intent and requirements, and are expected to enhance the visualization and accuracy of design information as well as advance design change management. information, and more advanced management. Meanwhile, when 3D models are used as the core of the approval process, it becomes essential for stakeholders to establish a common understanding on key practical matters—such as the scope of design information subject to approval, submission units, treatment of design changes and revisions, and the relationship with conventional 2D drawings. To facilitate the smooth introduction and establishment of 3DMBA, ClassNK considers it indispensable not only to develop supporting systems but also to clearly define the fundamental concepts and operational rules as an approval framework. In collaboration with ten Japanese companies, ClassNK conducted a joint pilot test to verify the feasibility of approval processes using 3D models*⁴, while also organizing practical challenges and lessons learned for real-world application. The guidelines published today consolidate these outcomes.

■ Key features of the guidelines

The guidelines organize practical considerations for implementing approval processes centered on 3D models, including:

• Principles for treating 3D models as approval deliverables
• The scope of design information subject to approval and submission units
• Principles for approval handling in cases of design changes and revisions
• Principles for using 3D models in conjunction with supplementary 2D drawings during a transitional phase
• Handling of 3D models in OCX format

■ Relationship with systems and guidelines

The guidelines are formulated on the basic premise of operating a 3DMBA-compatible system using ClassNK’s drawing approval management system “NK-PASS” and “ClassNK 3DViewer.” With this system release, it is now possible to submit and review OCX-based 3D models for approval, enabling an integrated operation of a 3D model-centric design approval process in accordance with the guidelines.

■ Next steps

ClassNK will continue to review and update the guidelines as necessary based on knowledge gained through actual operation and feedback from stakeholders. In addition, with a view to consistent utilization of digital data across the design and approval process, ClassNK will continuously consider and address further advancement of 3D model-centric approval processes and linkage with related business processes, while taking into account progress in international standards such as OCX and broader digital technologies.

■ How to access the guidelines

The guidelines are available to download via “Guidelines” of My Page on ClassNK’s website after registration.

https://www.classnk.or.jp/account/en/Rules_Guidance/ssl/guidelines.aspx

*1 NK-PASS:

A drawing approval management system provided by ClassNK. Traditionally used for 2D drawing approval, it will be equipped with functions supporting 3DMBA in this release, enabling approval processes using OCX‑based 3D models.

*2 ClassNK 3DViewer:

A 3D viewer under development by ClassNK is designed to render OCX‑based 3D models. It is intended for use in workflows centered on 3D models, including those under the 3DMBA framework, and supports broader utilization of digital data.

*3 Open Class 3D Exchange (OCX) format:

A type of file format that contains 3D model data and design specifications, developed to enable seamless digital workflows among shipyards and classification societies. It is a 3D digital protocol applicable to the design approval process for ships, and standardization is being advanced within a consortium comprising classification societies, 3D software vendors, designers, and related stakeholders.