FTA Studio vs PTC Windchill FTA (Relex)
If you learned fault tree analysis in the 2000s, you probably learned it in Relex. PTC acquired Relex Software in 2008, and that fault tree engine ships today inside Windchill Risk & Reliability — an integrated reliability suite wired into PTC's PLM platform. FTA Studio is a deliberately narrower thing: browser-based IEC 61025 fault tree analysis, free on Community, $99/seat/year for Professional. These tools are not really competitors so much as different shapes. Here's how to tell which shape you need.
At a glance
| FTA Studio | PTC Windchill FTA | |
|---|---|---|
| Lineage | Independent, built for the browser | Relex Fault Tree → PTC (acquired 2008) → Windchill Quality Solutions → Windchill Risk & Reliability |
| Deployment | Browser-based, nothing to install | Windows desktop, with client–server deployments against a shared database |
| OS support | Any OS with a modern browser | Windows only |
| Pricing entry point | $0 — Community, no expiry | Quote-based; not published |
| Scope | Fault trees: cut sets, quantification, Monte Carlo, importance measures | A reliability programme: prediction, FMEA/FMECA, FRACAS, RBD, Markov, maintainability, life-cycle cost, event trees and fault trees |
| Component failure-rate libraries | Reference tables; you supply the data | Built-in industry-standard prediction libraries |
| PLM integration | None | Native to Windchill |
| Sharing with people who have no licence | URL, or JSON anyone can re-open | Exported reports |
| Procurement | Sign up, or a card | Enterprise sales cycle |
| Support | Email; 24-hour first response on Enterprise | Enterprise contracts with named contacts |
The real difference is the data model, not the diagram
Both tools draw the same gates and compute the same minimal cut sets. IEC 61025 fixes the symbols and the maths, so a fault tree is a fault tree. Comparing them on gate types would tell you nothing.
What differs is what the fault tree is attached to. In Windchill, a basic event can be a part in a component library with a prediction-derived failure rate, the same part that appears in an FMECA and accumulates field failures through FRACAS, under PLM change control. Change the part, and the number moves everywhere. That is a substantial piece of engineering, and it is the actual product.
In FTA Studio, a basic event carries the failure rate you give it. The tree is a self-contained document. That is a limitation if you are running reliability as a programme across a parts database — and an advantage if the tree is the thing you were asked to produce, because there is nothing to configure before you start.
When to pick FTA Studio
- The tree is the deliverable. A safety case appendix, a customer submission, an ASIL decomposition argument — where the output is the analysis, not a maintained database.
- You need it this week. No install, no licence server, no procurement cycle.
- Your team isn't all on Windows. Reviewers on macOS or Linux open the same URL.
- Small team or contractor economics. $99/seat/year, and Community is free for up to 3 projects, 10 trees each, 3 members.
- Reviewers have no licence. Send a URL, or JSON they can re-open without buying anything.
When to pick PTC Windchill FTA
- Reliability is a programme, not a document. Prediction, FMECA, FRACAS and fault trees sharing one part model is exactly what the suite is for.
- You want curated failure-rate libraries. Built-in prediction standards beat sourcing rates by hand.
- You are already on Windchill. The PLM integration is real value you have already paid for.
- Automotive ISO 26262 at scale. FMEDA and FTA over shared part data is a workflow the suite is built around.
- Your customer or QMS names the tool. Some primes and quality systems do.
- You need named support and a vendor of record. Enterprise contracts, escalation paths, an org chart behind them.
Pricing — and why there is no number here
PTC does not publish list pricing for Windchill Risk & Reliability, and we are not going to invent one. What is public is the shape: enterprise licensing, quoted per deployment, typically scoped by module and seat count, usually with implementation alongside it. If you want a figure, PTC will quote you one; anything we printed here would be a guess dressed as a fact.
What we can state exactly is our side. FTA Studio Community is free, permanently — 3 projects, 10 trees per project, 3 members, no expiry and no node limit. Professional is $99 per seat per year. A five-person team is $495 a year, on a card, today.
Those two models are not really comparable, and the gap is not a claim that one is overpriced. An integrated suite with component libraries, PLM integration and named support carries costs a browser tool does not have. The question is whether you need what that money buys.
Standards coverage
Both tools implement the IEC 61025:2006 symbol set and the standard quantification primitives, and both are used in ISO 26262, ARP 4761, EN 50126, MIL-STD-882 and IEC 61511 work.
Neither tool makes your analysis compliant. The tool gives you the vocabulary and the arithmetic; the safety argument is yours to make and yours to defend. Our standards references map each clause to a concrete feature so you can check that claim rather than take it.
The TL;DR
Pick Windchill FTA if you are running reliability engineering as a discipline — a parts database, FMECA, field data, PLM — and the fault tree is one view of it. That integration is the product, and no browser tool replaces it.
Pick FTA Studio if the fault tree is the work: you need an IEC 61025-compliant analysis, built and reviewed and exported, without an install or a purchase order. It is the smaller tool, on purpose.
Windchill, Relex and PTC are trademarks of PTC Inc. FTA Studio is not affiliated with PTC. Product details here are drawn from publicly available information as of September 2026, and PTC's product naming and packaging have changed several times since the Relex acquisition. If something is out of date or wrong, email support@ftastudio.app and we will correct it.