Importing existing cases
Teams evaluating Lemmatica usually have an existing safety case in another tool — ASCE, NOR-STA, the legacy single-file HTML GSN editor that several teams still rely on, or hand-drawn Visio. The question is whether Lemmatica can take that work and continue it without forcing a rebuild from scratch.
This is the honest picture today.
Current status
Automated import is not yet available. A legacy import path is tracked on the roadmap but hasn't shipped. Until it does, getting an existing case into Lemmatica is a manual exercise.
If you're evaluating Lemmatica with a real existing case, two practical options:
Option 1 — Rebuild for evaluation
For a focused evaluation (say, a single hazard branch or a short module), rebuild it in Lemmatica. Most teams find this takes a couple of hours for a non-trivial fragment and gives them a fair feel for the tool. This is the path most teams have taken to date.
Option 2 — Wait for the importer
If your existing case is large enough that manual rebuild is impractical, the legacy importer is tracked work. Get in touch ([email protected]) and we can talk about timelines and what your existing format looks like.
What "importing" means in practice
GSN tools generally produce one of two artefact types:
- A graphical format (Visio shapes, ASCE's internal format) — these encode the visual layout but not always a clean structural model.
- An exchange format (the SACM / Structured Assurance Case Metamodel, OMG's argument interchange XMI, or a tool-specific export) — these are structural enough to migrate cleanly.
If your tool can export to SACM or any well-defined XML/JSON of the argument structure, the import is materially easier when it lands.
A note on the legacy single-file HTML GSN editor
A reference implementation of the original single-file HTML GSN editor (gsn_editor_v5_0_6_rc1_1.html and friends) is mentioned in CLAUDE.md as the predecessor to Lemmatica's design. Cases built in that editor will be among the first targeted by the importer.