Silicon Bring-up · All levels

Root Cause Closure and FA Handoff: Reports and Metrics

Reports and Metrics for Root Cause Closure and FA Handoff.

Reports and metrics

Reports and Metrics for Root Cause Closure and FA Handoff is anchored on Closure quality measured by root-cause confidence, mitigation durability, and FA turnaround from sample request to actionable evidence.. Convert observed behavior into mechanism-backed and owner-bound actions.

A useful report explains why behavior moved, not only that behavior moved.

Evidence matrix

diagram
EVIDENCE MATRIX - Root Cause Closure and FA Handoff

+-------------------------------+--------------------------------+--------------------------------+-----------------------------+
| Evidence                      | Tells you                      | Does not prove                 | Next action                 |
+-------------------------------+--------------------------------+--------------------------------+-----------------------------+
| rail/current timeline         | sequencing and power health    | firmware or protocol integrity | align with stage logs       |
| stage checkpoint logs         | failing transition boundary    | electrical root cause          | correlate with scope traces |
| interface trace/decode        | protocol behavior and timing   | global platform readiness      | replay under fixed setup    |
| shmoo/corner matrix           | margin-sensitive fail region   | exact failing mechanism        | isolate with targeted tests |
| before/after replay packet    | mitigation movement quality    | long-run stability             | run soak and corner matrix  |
+-------------------------------+--------------------------------+--------------------------------+-----------------------------+
  • Track Closure quality measured by root-cause confidence, mitigation durability, and FA turnaround from sample request to actionable evidence. on representative board and corner slices.

  • Include board/firmware/corner metadata in every report header.

  • Correlate electrical, software, and protocol evidence in one timeline.

  • Call out contradictory evidence explicitly.

Silicon bring-up deep dive

Triage quality is measured by how quickly teams converge from symptom to proven root-cause class with minimal collateral churn.

Concept diagram

diagram
TRIAGE CONVERGENCE

symptom -> classify -> isolate -> prove -> bounded fix -> replay

Metric graph

diagram
TRIAGE EFFECTIVENESS

wide speculative edits   ██████
classified bounded fixes █████████

Metrics and artifacts to collect

  • time-to-classification

  • first-failure artifact completeness

  • hypothesis branch conversion rate

  • post-fix recurrence trend

Mini case study

Intermittent field-like failures closed faster once teams forced one-variable branch tests and owner-tagged evidence packets.

Debug branches

  • Preserve first-failure state before reruns.

  • Use disproof-oriented experiments to collapse cause tree quickly.

  • Promote fixes only after recurrence tracking windows pass.

Senior review question

Ask: what is the first failing boundary, which artifact proves it, and who owns bounded closure?

Key takeaways

  • Tie every bring-up claim to one reproducible setup state and one proving artifact.

  • Prefer bounded fixes with clear owner and rollback trigger over broad multi-variable edits.

Common pitfalls

  • Running parallel uncontrolled experiments and losing causality.

  • Declaring closure without replaying across representative corners.

  • Escalating severity before bench/setup hypotheses are disproven.

Report interpretation

Interpret movement only when setup metadata is matched.

A useful report isolates first-failure stage and disqualifies alternate causes.