DISCUS vs 1Factory vs Paperless Parts: FAI Software Compared (2026)

I get asked about FAI software constantly. Quality engineers want to know which tool will actually speed up Form 3 preparation. Shop owners want to know which one is worth the investment.

After researching every major player in this space and talking to practitioners who use them daily, here is my honest comparison of DISCUS vs 1Factory vs Paperless Parts for FAI software, including what none of them fully solve.

Full disclosure: I build Mavlon, which is not FAI software in the traditional sense. It is a self-serve AI product that delivers a pre-populated Form 3.

I will explain where it fits at the end, but this comparison of DISCUS vs 1Factory vs Paperless Parts for FAI software. focuses on the three tools most aerospace shops evaluate when searching for FAI software.

If you are earlier in the search, our FAI software buyer guide compares the whole eight-tool field.

The short version

• DISCUS is the original desktop FAI tool. Great installed base, solid auto-ballooning on clean drawings, but it runs on your machine and still leaves the interpretation to you.
  
• 1Factory is a full cloud quality platform (SPC, CMM import, PPAP, CAPA). FAI is one module. Powerful, broad, and takes weeks to learn.
  
• Paperless Parts is a quoting and estimating tool for 3D CAD, not an FAI tool at all. It is on this list only because shops bump into it while searching.
  
• Mavlon is the AI that actually reads and interprets the 2D drawing, applies ISO 2768 by size, expands fit classes, classifies Boeing notes, captures the full GD&T datum frame, and hands you a filled AS9102 Form 3 in 2 to 3 minutes. It is the layer the other three are missing.

YOU NEED DRAWING ANALYSER NOT JUST AUTO BALLOONING

Reading the GD&T. Carrying the page-1 note onto the page-7 tolerance. Finding the right datums. That is the 90% no auto-ballooner does, and Mavlon does it in 2 to 3 minutes.

Bring your hardest drawing. Watch it become a Form 3 live.

The Three Tools: What Each One Actually Is

DISCUS (DISCUS Software Company)

How it works: You install DISCUS on your Windows computer. You open a PDF or TIFF drawing inside the DISCUS interface. You then either manually click on each feature to place a balloon and capture the data, or you use DISCUS IDA (Intelligent Drawing Analysis, their AI/OCR add-on) to auto-detect dimensions, GD&T symbols, and notes.

DISCUS creates the Bill of Characteristics (their term for the master list of all inspectable features) and generates AS9102 Forms 1, 2, and 3. The forms can be exported to Excel or directly to Net-Inspect.

DISCUS IDA specifically: IDA uses "customized Google-based OCR technology with unique image processing algorithms" (their published description) to read the drawing. Their own published benchmarks: manual extraction takes about 2 hours, OCR reduces it to 40 minutes, IDA reduces it to about 5 minutes for the extraction step. However, the quality engineer still reviews and corrects the output.

Strengths: Established product with the largest dedicated FAI user base. IDA auto-ballooning significantly reduces manual clicking on clean drawings. Direct export to Net-Inspect eliminates re-entry. Supports both 2D PDF and 3D CAD (with DISCUS 3D add-on). Desktop deployment means drawing data stays on your local machine, which simplifies ITAR compliance. Active development with DISCUS 10 recently released.

Limitations: IDA accuracy drops on feature control frames (GD&T) and notes, which are the hardest and most critical categories. Default tolerances must be manually configured before running IDA (you set the tolerance class, then IDA applies it). This means the quality engineer still needs to know which standard applies and configure it correctly. No feasibility analysis, no clarification question generation, no routing recommendations. Desktop-only means no collaboration features.

Weighing DISCUS against High QA instead? See High QA vs DISCUS.

1Factory

How it works: You upload a PDF drawing to 1Factory's web platform. Their OCR engine scans the drawing and identifies dimensions, GD&T symbols, and notes. You review the extraction, correct errors, place or adjust balloons, and 1Factory generates AS9102 Forms 1, 2, and 3. CMM data from Zeiss, Mitutoyo, Keyence, and PCDMIS can be imported directly into the form, closing the loop from drawing to completed FAI.

Strengths: Full quality platform (not just FAI). CMM data auto-import from major CMM brands closes the loop from extraction to completed report. Web-based means accessible from any browser, any location. SPC, gage calibration, PPAP, and NCR/CAPA management in one system.

FedRAMP and CMMC compliant for government/defense work. 21 CFR Part 11 validated for medical device manufacturers. Customer-specific FAI formats built in (Northrop Grumman, Lockheed Martin, Boeing-specific layouts). Active user community with 60+ reviews on Capterra and G2.

Limitations: The breadth of the platform means FAI is one feature among many. New users often take weeks to learn the full system. Per-user pricing with a five-user minimum is listed publicly.

The OCR extraction has similar accuracy limitations to DISCUS on GD&T and blanket tolerances. The "smart default tolerances" apply tolerances based on decimal places for US drawings (e.g., .XXX = +/-.005") rather than size-dependent lookup, which may not match the drawing's actual general tolerance specification.

Paperless Parts

How it works: You upload 3D CAD files (STEP, IGES, Parasolid) and Paperless Parts analyzes the geometry using AI to identify manufacturing features (holes, pockets, threads, surfaces) and estimate machining time and cost. The platform helps estimators price jobs faster by providing automated cost estimates based on the part geometry.

Strengths: Strong 3D model analysis and feature recognition for CNC machining. Good cost estimation for standard machining features. Growing integrations with ERP systems (JobBOSS, Epicor). Clean, modern interface. Well-funded and actively developing.

Limitations: Not an FAI tool. Does not generate AS9102 forms. Does not balloon 2D PDF drawings. Does not extract GD&T from 2D drawings. Requires 3D CAD files as input, but most aerospace subcontractors receive 2D PDF drawings from their customers, not native CAD. Does not handle blanket tolerance expansion or fit class resolution. US-focused with limited international adoption.

What none of them fully solve: The Interpretation layer

Every FAI tool I have researched, DISCUS, 1Factory, InspectionXpert, Net-Inspect, SOLIDWORKS Inspection, shares the same gap. They detect text. They do not interpret engineering. Size-dependent tolerances: ISO 2768mk gives a 12 mm dimension plus or minus 0.2 mm and a 305 mm dimension plus or minus 0.5 mm. Tools that apply one flat default get this wrong on every dimension outside that default's size band. ([the full table here](https://mavlon.co/post/as9102-form-3-for-iso-2768mk-drawings)) -

Fit class expansion. "9.0 G6" needs to become 9.005 to 9.014 mm on the Form 3. Neither DISCUS nor 1Factory expands fit classes; the engineer looks up ISO 286 by hand. ([G6 limits here](https://mavlon.co/post/blog-iso-fit-class-g6-tolerance-limits)) -

Boeing note classification. Deciding whether an untoleranced dimension is governed by Note 8N or 9N requires understanding the feature, not reading the text. OCR cannot classify features. How it works?

GD&T with the full datum frame. OCR catches GD&T symbols about 90 percent of the time on clean drawings. The 10 percent it misses (a datum C partially obscured, a concentricity read as runout) lands on the most critical rows, the ones that drive CMM planning and that customers scrutinize hardest.

This interpretation layer is the 90 percent of the work. The ballooning is the easy 10 percent. Every tool above automates the easy part and leaves you the hard part.

Where Mavlon fits: it does the interpretation

Mavlon is AI that reads the 2D drawing the way a senior quality engineer does, and it closes exactly the gap above. You upload a PDF and in 2 to 3 minutes you get back a ballooned drawing and a filled AS9102 Form 3 with:

• Blanket tolerances applied by size range, not a flat default.
• Fit classes expanded to their actual limits in mm.
• Boeing notes classified by feature type.
• GD&T captured with full datum reference frames and material condition modifiers.
  

It runs at about 90 percent accuracy and flags the 10 percent it is unsure about for your review, so your engineer spends 20 to 30 minutes checking a finished Form 3 instead of 4 to 5 hours building and correcting one.

It is a product you use, not a project. Cloud-based, any browser, no install. Your first drawing is free, and there is no enterprise minimum to get going.

And if you already run 1Factory, Net-Inspect, or DISCUS for CMM import and workflow, Mavlon's Form 3 drops straight in as the starting point, so you keep your system and just remove the part that takes all day.

Head-to-Head Feature Comparison (DISCUS vs 1Factory vs Paperless Parts for FAI software.)

The bottom line

If you want a full quality platform with CMM import and SPC, 1Factory is the broadest. If you want a proven desktop FAI tool that stays on your network, DISCUS is the safe pick. If you quote from 3D CAD, Paperless Parts helps with estimating, not FAI. But all three hand you a raw extraction and leave the reading to you, the part that actually takes the hours. Mavlon does the reading. Use it on its own, or feed its Form 3 into whichever of these you already own.

Bring Your Drawing to a Demo to see the difference on your own drawing. First drawing free.

FAQ: DISCUS vs 1Factory vs Paperless Parts

Is DISCUS better than 1Factory for FAI?

DISCUS if you want a dedicated desktop FAI tool that stays on your own network. 1Factory if you want FAI inside a full cloud quality platform with CMM import and SPC. Both are detection-first: the tolerance interpretation still sits with your engineer.

Does Paperless Parts do first article inspection?

No. Paperless Parts is quoting and estimating software built around 3D CAD. It does not balloon 2D drawings and does not produce AS9102 forms. It appears in FAI searches only because shops run into it while evaluating software.

What is the best FAI software for a small machine shop?

A browser tool with nothing to install and no platform onboarding. We wrote a separate guide on the best FAI software for small machine shops, and the full market comparison lives in our FAI software buyer guide.