Digital Mockup: from CAD Modelling and Verification to Augmented Design Review

Lionel Grealou CAx Data 3 minutes

Parameterisation of Computer-Aided Design (CAD) models provides assistance to designers and engineers in making manufacturing related decisions, in combining creation feature and geometric parameters.

Historically, the Digital Mock-Up (DMU) has been a CAD based purpose-build realistic prototype or computer simulation which is central to the virtual aspects of the product development process.

Robinson et al. (2018)

The DMU is a mean to an end and part of a product development process: it consists of a digital representation of a product together with its product structure and related attributes. Over the years, it became a standard to support virtual product development in simulating and anticipating both design (concurrent functional views) and production (process-oriented / manufacturing / assembly views) questions.

CAD assists design engineers in the modelling, selection, re-use of data and documentation in the product design phase, and DMU enable design engineers, assembly and manufacturing planners as weIl as management to simultaneously develop product and production.

CAD generated 3D models are one element of the DMU (…); others elements comprise metadata (attributes) and product structures feeding multiple Bills of Materials (BOM).

Dolezal (2007)

Certain schools of thought do not differentiate CAD product structures and engineering BOMs (“as-designed” BOMs), while it makes more sense to consider the former as a sub-set of the later due to other enterprise information which contributes to the design and engineering of a product. This is especially relevant for complex products, such as highly configured products and those with wide supplier base or large number of components.

Image credit: Dolezal (2007)

In a given context, the DMU “system” (not in terms of IT system, but “configured product” DMU) is relevant for all technical teams as it provides multiple representations of the CAD models (including multi-CAD models) with associated metadata:

  • As-designed and as-planned views of the 3D models, including parametric, part and assembly models
  • Contextual product structures which can be filtered by attributes or configured variants, as well as by functional components
  • Space allocation models to allow for concurrent engineering and interfacing (across functions and / or product variants or platforms)
  • Detailed models, based on data maturity and function
  • Simulations and associated results (e.g. clash, calculated weight and balance, kinematics, thermal, finite elements, etc.)
  • Associated 2D drawings, geometrical tolerances and technical publications and specifications
  • Data exchange packages (across teams, organizations, applications, neutral formats, etc.)
  • Business analytics and attribute-based color-washing against 3D representations, including CAD data and BOM quality reporting (e.g. adherence to design and release standards)

DMU supports concurrent engineering through the coordination of parallel development activities within a team of engineers. It is therefore a key enabler for systems engineering practices, closing the loop between multi-functional activities and systems, from design, engineering, manufacturing, programme management and other enterprise functions.

DMU is moving out of the CAD environment, making it available to users who do not have a CAD system.

CIMdata (2007)

CAD, metadata and product structure management quality alignment is an essential pre-requisite to successful DMU for effective product creation, especially when used in (but not limited to) discrete manufacturing industries such as mobility and transportation. Broadly speaking, DMU provides a bridge between virtual environments and virtual objects, from which CAD 3D models are the primary reference data to perform virtual assembly to complete engineering evaluation (Zhang et al., 2012).

In most cases and industries, DMU potential can be fully exploited only through business practice adjustment, through a combination of organizational changes and changes in the development process. Ultimately, DMU links to virtual reality (VR) with further opportunities to immerse users inside CAD and its related product structure and attributes.

What are your thoughts?


  • Dolezal WR (2007) Success Factors for Digital Mock-ups (DMU) in complex Aerospace Product Development. Technische Universität München Institut für Luft- und Raumfahrt (ILR)
  • Robinson T, Friel I, Armstrong CG, Murphy A, Butterfield J, Price M, Marzano A (2018) Computer-aided design model parameterisation to derive knowledge useful for manufacturing design decisions, Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 232(4), pp. 621-628
  • Zhang HY, Li J (2013) Modeling Method and Application in Digital Mockup System towards Mechanical Product, Advanced Materials Research, Vols. 605-607, pp. 604-608

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About the Author

Lionel Grealou


Lionel Grealou, a.k.a. Lio, helps original equipment manufacturers transform, develop, and implement their digital transformation strategies—driving organizational change, data continuity and process improvement, managing the lifecycle of things across enterprise platforms, from PDM to PLM, ERP, MES, PIM, CRM, or BIM. Beyond consulting roles, Lio held leadership positions across industries, with both established OEMs and start-ups, covering the extended innovation lifecycle scope, from research and development, to engineering, discrete and process manufacturing, procurement, finance, supply chain, operations, program management, quality, compliance, marketing, etc.

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