progress = (TRL / 9) × spec fraction
TI = 1000 × Σ(w · progress) / Σ(w)
Forty-four components across fourteen categories, total weight 313. Weights are editorial and published: they state how load-bearing a component is for fielding a Terminator, not how interesting it is.
A one-to-nine ladder mirroring NASA's Technology Readiness Level, applied to a different destination. One is “the physics permits it”. Nine is “in routine operational use, at the required specification”. We score the best demonstrated system in the world, not the median one.
How much of the canonical requirement the best real system meets. A mature, fielded technology delivering three per cent of what the films require scores 0.03. Each entry states the comparison, so the number can be argued with.
Dated, cited, resolving evidence, and nothing else — papers, spec sheets, benchmark tables, filings, regulation. Retractions and failed demonstrations move it down. An index that only rises is not an index.