Improving CAD data quality in Siemens NX – methods and tools
Key points at a glance
- Faulty CAD data in Siemens NX leads to additional costs throughout the entire product lifecycle management process chain – from development through to manufacturing and service
- The most common sources of error are inconsistent layer assignments, incorrect PMI information, failure to comply with modelling standards and geometric inconsistencies
- Automated checking tools detect these errors directly within Siemens NX and rectify them – without designers having to know the rules by heart
- Companies that systematically ensure CAD data quality reduce rejections, shorten lead times and create a stable foundation for all downstream processes
Why is CAD data quality in Siemens NX so important?
The quality of CAD data has a decisive influence on costs throughout the entire product lifecycle management process chain – from development through to production and servicing. What begins as a minor error in design can lead to significant delays in manufacturing and costly rework during assembly.
The complexity of modern industrial products is constantly increasing: machines today contain tens of thousands to hundreds of thousands of components, design teams work across multiple sites, and the demands on data quality are rising in all downstream processes.
Poor-quality CAD data typically causes:
- Workflow rejections due to missing or incorrect data in the 3D model
- Long lead times due to manual verification and correction
- Increased coordination effort between design, manufacturing and procurement
- Inconsistent models that hinder stable further development
What are the most common CAD data errors in Siemens NX?
In practice, similar types of errors recur time and again in Siemens NX:
Geometric inconsistencies Gaps, overlaps or sub-optimally defined feature elements can affect downstream processes – particularly CNC machining and simulation.
Incorrect or incomplete PMI information Product and manufacturing information (PMI) must be recorded completely and correctly. Missing dimensions, incorrect tolerance specifications or incomplete surface definitions lead to misunderstandings in manufacturing.
Failure to adhere to modelling standards Layer assignments, wave geometries, naming conventions and scales must be consistently adhered to across the organisation. Deviations often arise not due to negligence, but because designers do not have the extensive set of rules fully in mind.
Inconsistent assembly structures Incorrect links or relationships within assemblies often only become apparent in downstream processes – once the data has already been passed on to production or procurement.
Non-standard off-the-shelf parts Using non-standardised screws or bores, even though suitable items are available in the standard range, results in unnecessary additional costs.
How was CAD data quality checked in the past – and why is that no longer sufficient?
Until a few years ago, manual checking was the only option: designers checked their models using checklists, logs and macros – a time-consuming, error-prone process.
GRIMME Landmaschinenfabrik GmbH & Co. KG, one of the leading manufacturers of agricultural machinery for potato, beet and vegetable cultivation, describes the situation prior to the introduction of an automated solution as follows:
“Before using DQM, we carried out model quality checks – insofar as this was even possible – manually, which was a labour-intensive process. Some errors only came to light when the data was actually used. It was not possible to efficiently implement and enforce the specified requirements and regulations.” – Markus Frommeyer, PLM Consulting Department, GRIMME Landmaschinenfabrik GmbH & Co. KG
For products with up to 300,000 components per machine, manual checking is neither scalable nor reliable. The approach was clear: to automate quality checking directly within the design tool.
How does automated CAD data quality checking work in Siemens NX?
Modern tools for CAD data quality checking are integrated directly into Siemens NX. They automatically check drawings, parts and assemblies of any complexity – without switching systems and without designers having to open additional software.
Typical functions:
Automatic checking against best-practice rules Predefined checking rules cover all relevant quality criteria – layer assignment, geometry, PMI, standard parts, model structure. Rule profiles can be configured uniformly across the organisation and used at all sites.
Suggested solutions rather than just error messages Instead of merely identifying problems, modern tools provide concrete suggestions for corrections. The ‘healing’ function rectifies common errors automatically or at the touch of a button – without the designer needing to know the rule off by heart.
Graphical reporting Detailed reports for individual objects or assemblies provide managers with an overview of the current quality status at any time – and thus a solid basis for approval decisions.
Configurable error classification Rule violations can be classified as errors that prevent approval or as warnings – depending on internal company priorities.
What results do companies achieve in practice?
Two real-world examples from the mechanical engineering sector illustrate the typical benefits:
GRIMME Landmaschinenfabrik GmbH & Co. KG GRIMME has been using the DOCUFY CAx Quality Manager since May 2019. Around 120 staff members in the development department use the software. Markus Frommeyer, PLM Consulting Department:
“Data quality and the structure of CAD models have improved enormously. There is a more consistent structure in the components and assemblies. Incorrect relationships or links are detected and rectified at an early stage. DQM relieves us of a huge amount of checking work – and it’s so easy to use.”
“The introduction of DQM has taken us a big step towards improved data quality. We wouldn’t have thought this possible without a great deal of effort in implementing the software or training users.”
Maschinenfabrik Berthold Hermle AG Hermle, a leading manufacturer of 5-axis machining centres with 1,000 employees, has been using the DOCUFY CAx Quality Manager since 2016. Lars Fröhlich, IT/PLM Systems Manager:
“With the DOCUFY CAx Quality Manager, our design engineers can concentrate on their core competence: the design of machines.”
“A small error in the design can cause massive delays and high costs. We are extremely pleased that, with the DOCUFY CAx Quality Manager, we can rely on optimum data quality. All it takes is a single press of the ‘Healing’ button.”
What is the DOCUFY CAx Quality Manager?
The DOCUFY CAx Quality Manager (DQM) is a tool for Siemens NX designed for the automated checking and optimisation of CAD data. It provides over 400 best-practice checks as standard, offers automated healing functions and can be used immediately without the need for extensive training. The tool is fully integrated into Siemens NX and supports the current NX version 2512.
DQM is used by over 550 companies and was developed in collaboration with Heidelberger Druckmaschinen AG. A 90-day trial licence with full functionality is available to help you get started quickly.
FAQ: Frequently asked questions about CAD data quality in Siemens NX
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Faulty CAD data leads to additional costs throughout the entire PLM process chain – from design through to manufacturing and service. Errors detected early on are significantly cheaper to rectify than those only noticed during production or at the customer’s site.
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The most common types of errors are inconsistent layer assignments, incorrect or incomplete PMI information, failure to comply with modelling standards, geometric inconsistencies and non-standardised off-the-shelf parts.
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Specialised tools such as the DOCUFY CAx Quality Manager check CAD data directly within Siemens NX against configurable best-practice checks – without switching systems. Errors are automatically detected and can be rectified directly using the ‘healing’ function.
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The effort required is minimal. GRIMME Landmaschinenfabrik reports that the tool could be introduced without significant implementation or training effort. A twelve-page handout was sufficient to get the team up and running.
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For all companies that use Siemens NX and whose CAD data feeds into downstream processes such as manufacturing, simulation or PLM – in other words, practically every industrial Siemens NX user.
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A 90-day trial licence with full functionality, including installation, configuration and support, is available for a no-obligation trial. Further pricing information is available durin
