What the data shows
Five findings from 336 responses, 134 products named, and 4,777 source citations.
Siemens is the clear leader
Opcenter is named in 83 of 112 prompts and appears in all eight buyer segments on all three engines. No other vendor clears 50 percent coverage on more than one engine. The lead holds under every weighting method tested, so no methodological choice threatens it. What makes the position unusual is that it rests on training recall and retrievable content simultaneously: Siemens has the largest own-domain citation footprint in the study, with 107 citations on ChatGPT alone.
The three engines are not measuring the same market
Critical Manufacturing is named in 52.7 percent of ChatGPT prompts and 17.9 percent of Perplexity prompts. iFactory, a product most people in this category have never heard of, appears in 12.5 percent of Perplexity prompts and none at all on ChatGPT. Of the 847 domains cited across the study, only 21 were cited by all three engines and 536 were cited by Perplexity alone. A vendor measuring its AI visibility on one engine is measuring roughly a third of the picture, and possibly the wrong third.
Visibility comes from two separate mechanisms
For every vendor mention we checked whether the same engine cited that vendor's own website in the same answer. ChatGPT did so 68 percent of the time, Perplexity 24 percent, Gemini 9 percent. That test separates vendors the models remember from vendors the models can find. Some names appear in dozens of prompts with almost no supporting citation anywhere, which means their visibility rests entirely on training data. That is a durable position and also one that publishing cannot improve.
Buyer segment changes the answer more than anything else
Five vendors that sit outside the overall top nine lead or place second in a single segment. MasterControl ranks tenth overall and first in medical device. Aegis ranks seventh and first in electronics. Applied Materials ranks eleventh and second in semiconductor. iBase-t ranks twelfth and second in aerospace. First Resonance ranks thirteenth and second in hard tech. Each of them appears in 11 to 13 of the 14 prompts in their home segment and almost nowhere else.
Adjacent categories take a quarter of the answers
Only 62 percent of product mentions were core MES or MOM products. ERP took 17.6 percent and PLM 6.7 percent. SAP S/4HANA ranks seventh across all products and Siemens Teamcenter eighth, ahead of every specialist MES vendor except the top six. The competitive set in AI answers is wider than the competitive set in a normal deal cycle, because the engines reproduce the buyer's existing mental model, and that model already has ERP and PLM in it.