What is PMI (Product Manufacturing Information)?
Product manufacturing information (PMI) is essential engineering or manufacturing information embedded within a 3D CAD file. It is governed by ASME and ISO industry standards.
PMI may include the following information:
- GD&T (Geometric dimensions & tolerances).
- Bill of materials (BOM).
- Surface finish.
- Weld symbols.
- Material specifications.
- Metadata & notes.
- History of engineering change orders.
- Legal/proprietary/export control notices.
- Other definitive digital data.
3D PMI is a significant step to digital transformation and quality control for any company or department.
Once design engineers complete their 3D CAD, they spend additional time to create 2D drawings from their 3D design to convey product & process information such as GD&T.
Then manufacturing or quality control engineers rely on those 2D drawings to MANUALLY enter GD&T and other data into their CMM (coordinate-measuring machine) or CAM (computer-aided manufacturing) software– occasionally, interpreting ambiguous data from 2D designs.
Converting and relying on 2D drawings are unnecessary when essential & correct data can already be included within the 3D CAD. This frees up time & resources for design and manufacturing and highly reduces the potential for error.
More importantly, this becomes a starting point to bridge departments and companies into digital transformation & automation.
Top 10 Pitfalls of 2D Drawings
- Not machine-readable
- 3D visualization is mainstream, mobile, and affordable.
- Wasted effort to recreate 2D from 3D.
- Less information available — the product will exist in 3 dimensions, why reduce its definition to 2?
- More prone to interpretation and data inaccuracies. Up to 60% of 2D drawings do not match 3D models.
- Aren’t adequate to convey design intent.
- More back and forth and time wasted on clarifying designs.
- Not suitable for cross-department collaboration.
- Another document to the pile & workflow.
- Simple change in production definition requires changes to all 2D documentation.
Semantic PMI + 3D CAD = The Key to Model-Based Definition
The process of applying PMI to the 3D CAD as the one authority model from design to production is called MBD (model-based definition).
PMI can be broken down into two levels.
The first is graphical PMI or human-readable PMI. The 3D annotations are included in the model, but cannot be read by machines. So while the tolerances and dimensions are digitally included, it's not consumable downstream. Essentially, it's a half-step towards MBD.
The second is semantic PMI or machine-readable PMI. It is human-readable and also consumable by machines/computers for downstream use in CAD, CAM, and CMM. This is true manufacturing automation that is the intent of MBD.
MBD aims to maintain continuity throughout the downstream process, because various documents & engineering changes like updating the 3D model but not updating 2D drawings and vice versa lead to unintended deviations that either slow down production or at worst, produce an inaccurate part.
This can cost a company thousands to hundreds of thousands of dollars because of one simple GD&T mistake.
This mistake happens because 3D models are machine-readable, but 2D drawings are human-readable. And when dealing with different CAD/CAM systems from different companies sharing with different departments with different processes, the complexity and potential for oversight & redundancies only increases.
Integrating PMI into 3D CAD allows one file to be machine and human-readable thus improving efficiency. Therefore MBD and the model-based approach hopes to reduce time, save costs, and streamline processes.
The practice of using 3D CAD + PMI has proven to save up to 80% of time from design to production to quality control compared to 2D drawings and the drawing-centric approach.
Need to Learn More About Applying PMI to Your 3D CAD?
Starting a pilot program or need to learn more about MBD process or tools? Contact us today and become the spark that brings your company into the digital age.
21 Reasons Why PMI (Product Manufacturing Information) is Important
- Man hours saved: up to 80% time saved compared to drawing-centric approach.
- Frees up engineering time for improving design and products.
- Communicates designer’s intent.
- Next generation of engineers see and design in 3D.
- Improves engineer skillset to learn and apply new insights.
- Single source of truth & data authority.
- Reduces human error through typing or interpretation.
- Eliminates redundant annotations.
- Up-to-up information embedded & easily revisable.
- Machine-readable 3D CAD & PMI for automation.
- Removes the “middle man” or engineering drawings.
- More feature-rich data for better instructions for the end-user.
- More iteration and process breakthrough improvement.
- Higher quality inspections with measurement optimization algorithms.
- Reusable information housed in a single source across multiple lifecycles & processes.
- Better two-way communication and easier collaboration among stakeholders.
- Part of MBD process: Better products, better pricing, better margins.
- Shorter product development cycles, faster time to market.
- Global interoperable standard at the software level.
- Enables MBE (model-based enterprise): Staying competitive, first-mover advantage.
- Scalable practice from one part to one department to one factory to enterprise-wide.
What are the Challenges to Adopting PMI?
First is the cultural challenge. Traditional practices and processes are about repeatability & stability.
“If it ain’t broke, don’t fix it.”
However, with the dynamic changes in today’s business climate, time-to-market along with innovation & cost-cutting is the three-headed monster companies must face in staying relevant as competition advances.
The horse was just fine...until Henry Ford produced a “faster horse.”
Second is a lack of CAD software support for 3D GD&T and file compatibility from vendors such as NX, CATIA, Creo, Solidworks, and others. With different companies, departments, and suppliers using different CAD/CAM software, file translation, validation, and compatibility become a major roadblock.
Third is a lack of formal training and skills to create and interpret 3D GD&T. A mistake made during design becomes a classic case of garbage in, garbage out downstream.
Therefore layout, symbols, and formatting to best and accurate practices (e.g. ASME 14.5, ASME Y14.41) is crucial to having proper and reusable PMI. As MBD adoption grows–culture, company, and skills will begin to understand and incorporate PMI and its benefits.
Benefits of PMI By Department
How PMI Affects Design
While initial MBD annotations does increase amount of hours in the early run, downstream it provides from 65% to 80% time savings immediately for annotation, machining, and inspection processes together.
And as engineers learn how to properly define machine-readable PMI, MBD annotations become faster than 2D.
How PMI Affects Manufacturing & Quality Control
A study by Capvidia presented at NIST (National Institute of Standards and Technology) shows up to an 81% time reduction for CMM process when using MBD.
How PMI Affects Business
The average salary for a design, mechanical, and quality control engineer ranges from $60K to $82K a year with top earners above $125K. With taxes, benefits, overhead, and other employee investments, the fully burdened cost is probably 2X an engineers salary.
With up to 80% time & work reduction, this either frees up skilled engineers to work on other projects or refine current ones for breakthroughs.
It also eliminates redundancies for a better product and bottom line.
How to Implement PMI?
- Define people who are directly involved with 2D drawings.
- Document current practices, communication exchange, and technologies.
- Identify a pilot project.
- Get design or drafting team to start implementing PMI onto 3D model.
- Work with downstream departments and team to use 3D model + PMI.
- Track progress.
- Measure ROI.
- Take insights and expand into next MBD project while building up MBD education.
Need Help Integrating PMI to Your 3D CAD or MBD process?
Contact us today and our solutions team can answer every question you have from multi-CAD compatibility to First Article Inspection.