Separate the tree from the investigation
A family tree models relationships. A case system should also model the research question, searches, evidence, conflicts, hypotheses, tasks, and conclusion history.
Preserve provenance
Documents should retain source URL or repository information, access details, related people, citations, and why the evidence matters.
Support negative research
Professional systems should make it possible to record searches that produced no result instead of only storing successful discoveries.
Handle DNA as evidence, not magic
Useful DNA tools connect match metadata, shared matches, cM, segments, relationship hypotheses, and documentary identities without pretending a match amount alone proves a relationship.
Export and hand off cleanly
Researchers need reports, portable data, version history, and a way to preserve the reasoning trail when a case is reviewed, transferred, or closed.