Blog/Governance
Lineage and Controls for Model-Driven Decisions
·~15 min read
Why reproducibility is a control: versioned assumptions, immutable logs, and separation of duties in AI-augmented workflows.
Reproducibility as a control
When AI assists drafting or extraction, the control is traceability: which prompt, which document snapshot, which approver, and which model version produced a number suitable for the IC deck. Reproducibility is not academic—it is how risk teams sleep at night when tools move fast.
Versioned assumptions
Material assumption changes should behave like pull requests: diff, reviewer, approval, merge. "The model moved" is not an explanation—"WACC moved from 9.2% to 9.5% per risk memo v4 approved by Jane on 12 March" is.
Prompts & document snapshots
Store prompt templates and retrieved document hashes with outputs. If an LLM claims customer concentration is 18%, the workpaper should link to the PDF page range and the extraction run ID—not a chat thread that scrolls away.
Separation of duties
Builders should not be sole reviewers of material outputs. Separation between build and challenge roles scales when systems enforce it—dual approval on assumption packs, read-only IC snapshots, and locked periods after sign-off.
Immutable logs
Append-only event logs for model runs, data imports, and AI-assisted summaries create defensible history. Mutable logs are worse than no logs—they imply rigor while allowing silent edits.
IC-ready workpapers
Treat prompts, retrieved documents, and approvals like workpapers—so IC materials stay traceable when tools move fast. Partners should sign narratives they can reproduce, not paragraphs nobody can source.
Audit & diligence
External diligence will ask how AI is governed. Have answers ready: human-in-the-loop gates, prohibited autonomous actions, data retention, and subprocessors. Governance is a sales asset when allocators compare platforms.
Closing thought
Lineage and controls do not slow teams down—they prevent rework when someone asks "where did this number come from?" six months later. Build traceability in by default.
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