Carefully toleranced critical dimensions on a beautifully planned out engineering drawing don’t mean much if, in practice, they all go out the window due to a sloppy manufacturing process. If you’ve heard the phrase “the drawing is the contract” then First Article Inspection or FAI reports are the means by which said contract is enforced.
For manufacturers, FAI reports represent a way to show to a client that they are holding up their end of the bargain. Discerning customers buying parts from manufacturers can conduct their own FAI to verify the manufacturer’s work before putting those parts into service.
First Article Inspection and AS9102
The AS9102 template serves as one of the most widely used standards for First Article Inspection. Originally developed for the aerospace industry, variations on this template are used throughout all kinds of quality control departments around the world.
Most notably, it includes rows for each “characteristic” which represent every dimensional requirement or note of an engineering drawing, with columns for the tolerance limits established by the drawing and the results measured off the sample part(s).
Figure 1. Snippet of example AS9102 Form 3.
Accompanying the AS9102 form is a “tagged” or “ballooned” drawing that associates each characteristic with the callout on the drawing.
Figure 2. Example ballooned drawing view.
Generating a First Article Inspection form using a manual process means “ballooning” each characteristic and, at a minimum:
- Mapping over the nominal value of the characteristic and its location on the drawing.
- Noting the tolerances of the characteristic.
- Computing upper and lower limits based on tolerances and nominal dimensions.
This manual process may be manageable for simple drawings, but as the number of drawing sheets and dimensions per view grows, it quickly becomes unsustainable without an automated tool. With so much transcribing required, this manual process is also rife with the opportunity for error.
Statistical Process Control
Statistical Process Control, or SPC is a term that should be familiar to any company employing or pursuing lean manufacturing, such as Lean Six Sigma. SPC involves performing inspections on a statistically significant number of sample parts during or after a production run. This is made feasible by inspecting a reduced set of characteristics—often only the most critical dimensions.
By sampling a significant number of samples, statistical analysis is performed to predict failure/rejection rates before the parts ever make it to FAI and understand how tightly the process is controlled.
SPC employed in-process can even catch tool wear issues, a degrading piece of machinery and other problems before they happen.
The automotive industry relies on a part release program called PPAP (Production Part Approval Process) that combines first article inspection and SPC.
SOLIDWORKS Inspection Software
SOLIDWORKS Inspectionis a software package that automates inspection report creation for both First Article Inspection (FAI) and Statistical Process Control (SPC). It provides a variety of means for automatically extracting characteristics from a part or drawing, mapping the requirements into the appropriate form along with location callouts and automatically computing the upper and lower limits from tolerance information.
The tool can be used as a standalone software by Quality Control personnel who may not even have access to CAD, or as a SOLIDWORKS add-in to allow leveraging of SOLIDWORKS native data.
SOLIDWORKS Native Inspection Report Creation
Creating an inspection report based off SOLIDWORKS native data is a straightforward process with the SOLIDWORKS Inspection add-in. A prompt to create the Inspection report allows the user to select a template, establish the “default” tolerances for when no specific tolerance is specified, and reference SOLIDWORKS custom properties for information such as Part Name and Part Number.
Finally, Extraction Settings are adjusted to control which characteristics (dimensions, notes, hole callouts) will be automatically ballooned and extracted from the file.
Once the checkmark is clicked, SOLIDWORKS Inspection combs over the drawing and tags the relevant dimensions, while building a list of Characteristics visible in Figure 3 below.
Figure 3. Inspection project prompt and extracted characteristics.
This list of characteristics represents a preview of the data that will be exported to the relevant inspection form template. SOLIDWORKS Inspection ships with a number of templates including AS9102 variants and several templates for process control. The Microsoft Excel templates can be fully customized to inject company branding or make any other modifications required to formulas and data.
Figure 4. SOLIDWORKS Drawing set to extract only dimensions marked for Inspection.
In addition to the ability to extract data from 2D SOLIDWORKS drawings, the Inspection add-in can also extract data directly from SOLIDWORKS 3D CAD models prepared for Model Based Definition.
Figure 5. SOLIDWORKS MBD-enabled model with characteristics extracted.
Forward-looking organizations embracing MBD may find that the Product Manufacturing Information or PMI associated to the CAD model can also be used in other downstream software, such as by their CNC and CMM programming tools.
PDF-Based Inspection Report Creation
SOLIDWORKS Inspection Standalone is primarily used for inspection report generation using PDF versions of engineering drawings. This is useful for manufacturers and machine shops that may not be provided with the SOLIDWORKS native documents, or the worker in Quality Control who may not have access to a SOLIDWORKS CAD license.
While not fully automatic like the add-in, the standalone tool can extract any text data directly embedded in a PDF, as is common with many drawings created using “Save as PDF…” from a CAD system. If that doesn’t work, it will fall back to an OCR or Optical Character Recognition based extraction method.
Smart Extract functionality allows box selecting around batches of dimensions and automatically extracting their characteristics.
Figure 6. Smart Extract tool in SOLIDWORKS Inspection.
In the figure below, a selection box is dragged with Smart Extract around multiple ordinate dimensions. These dimensions are extracted with their nominal values and tolerances, and are populated into the characteristic list, ready for export.
Figure 7. Smart Extract being performed on a batch of dimensions.
Quality Control personnel often appreciate the extra control that this “semi-automatic” extraction process provides them. For example, they can easily split out hole callouts into multiple separate characteristics, or group them into one characteristic in the event they will be inspected with a Pass/Fail gauge.
Stubborn PDFs may necessitate more careful box selection around each individual characteristic for extraction. If necessary, a fallback option to improve performance is to develop a custom OCR dictionary, which involves training the software on a set of sample drawings. This can be worth the effort if dealing with a large volume of drawings with a strange font, hand-drawn documents, or otherwise poor-quality scans—but should be a rare exception as the OCR choices built-in cover a wide range of common CAD software.
Inspection projects that were initially created in the add-in from SOLIDWORKS native data can also be exported to the SOLIDWORKS Inspection standalone tool. This means that engineers or designers may create a starting point for the inspection report based off the native SOLIDWORKS data, and the workers in quality control can make final adjustments.
Figure 8. PDF-based drawing comparison.
Also possible is the ability to perform a PDF-based change comparison of multiple drawings, where the new or modified characteristics will be automatically highlighted, and even swap out the underlying PDF for a new revision. This makes it possible to update an inspection project for new revisions of engineering drawings without starting from scratch.
External Measurement Input & QMS Export
The functionality covered so far pertains to generating an inspection report to be filled out with measurements later. The process can be taken a step further to enable measurement input directly into the SOLIDWORKS Inspection software—meaning a completed inspection report with measurement results and Pass/Fail status will be directly exported from the software.
Measurements can be input by manual typing, USB-based digital calipers or imported from external measuring device. Regardless of the approach, there is dynamic highlighting of the measured value and associated characteristic for color-coded and adjustable pass, fail and warning conditions.
Figure 9. Direct measurement input and results-based highlighting.
Most utilizing external measurement import take advantage of the CMM Data Import function, which allows importing raw measurements exported from a variety of digital measuring machines such as CMM, Faro arm or optical comparator. A variety of built-in templates are included for translation of common measurement formats and controller software, such as PC-DMIS.
Figure 10. CMM Data Import.
An important note is that the SOLIDWORKS Inspection software doesn’t replace software to program a CMM machine or other measurement device; instead, its capabilities lie solely in report generation and publishing.
Besides publishing a ballooned PDF and populated Excel report for first article inspection or process control, SOLIDWORKS Inspection can also export results directly into third-party Quality Management Systems(QMS) and inspection tools such as Net-Inspect and Verisurf to further streamline operations.
Figure 11. Publishing options.
Functionality Tiers
The Standard version of SOLIDWORKS Inspection includes the vast majority of functionality, including the ability to function as an add-in for automatic extraction of characteristics from SOLIDWORKS native drawings, or as a standalone software for inspection report generation from PDF drawings.
Features exclusive to the Professional version include:
- External measurement input and CMM data import.
- Graphical pass/fail status highlighting.
- 3D CAD or MBD-based inspection.
All versions include out of the box Excel export templates for AS9102, PPAP and process performance/SPC that can be further customized if needed.
Summary & Conclusion
First article inspection reports are a powerful and necessary tool for manufacturers and their clients alike, to ensure they hold each other accountable for the specifications presented by their engineering drawings. Historically these reports have been an extremely tedious type of documentation to produce, but it’s now possible to use a CAD-embedded solution that will virtually eliminate the grunt work of transcribing data and double-checking computed limits for dimensions to easily export reports.
Even for PDF-based drawing prints, advances in technology like Smart Extract and Optical Character Recognition have made semi-automatic extraction faster and more reliable than ever.
Organizations looking to be on the leading edge of technology can take advantage of rapid inspection report creation for their Statistical Process Control, or MBD-based inspection report generation for drawingless environments.
To learn more about SOLIDWORKS, check out the whitepaper Developing Better Products in the Cloud.