Hi Jason,
Although Ishikawa's idea of a diagram that looks like a fishbone is visually appealing, it is very hard to automatically arrange and no official studies have actually been made on haw to draw such diagrams automatically.
It is also not well (if at all) standartized, so anyone who claims he draws Ishikawa's diagrams is actually making free hand drawings that look like fishbones. Most of the Ishikawa diagrams that you see on the net (if not all) are manually created, as is the case with competitive products that claim to support, such diagrams.
The Nevron Diagram has all the primitives you need to implement such a diagram, but the automatic layout of such a diagram is by no means easy. If you can find any academic materials on this matter - please share them with us, so that we can research a possible automatic arrangement.
The closest analog to Ishikawa layouts is the Tip Over tree layout.
Best Regards,
Nevron Support Team