ECO Regression Discipline: Review Checklist

Review checklist

Review Checklist for ECO Regression Discipline focuses on post-ECO regressions caught, corner coverage, signoff approval latency. The goal is to connect observed QoR movement to mechanism, ownership, and regression risk.

• Run manifest is attached (RTL/SDC/libs/switches).

• Primary metric and impacted lane are named.

• Mechanism hypothesis is evidence-backed.

• Fix is reversible and owner-assigned.

• Regression matrix includes timing, area, power, and equivalence as needed.

• Owners signed: timing closure lead, verification owner, program owner.

Sign-off ownership

OWNERSHIP MAP — ECO Regression Discipline

artifact              owner
----------------      -----------------
compile owner       timing closure lead
timing/power owner  verification owner
cross-team review   program owner

Every QoR movement needs a named owner before ECO.

Synthesis deep dive

Incremental and ECO synthesis protect schedule only with strict regression discipline.

Concept diagram

INCREMENTAL ECO LOOP

identify delta -> localized compile -> patch -> regression -> release

Metric graph

ECO CYCLE TIME

full compile      ███████████
incremental       █████

Reports and artifacts

• incremental reuse

• ECO patch list

• LEC status

• regression matrix

Mini case study

Localized compile cut turnaround 40%, but skipped LEC caused rollback.

Debug branches

• Reuse ratio is not enough

• Patch locality check

• Always include equivalence hooks

Senior review question

Ask: what evidence proves this QoR move is real and stable?

Key takeaways

• State exact run context (RTL, SDC, libs, switches) with every QoR claim.

• Re-run timing, area, and power regressions after each synthesis ECO.

Common pitfalls

• Comparing runs with mismatched constraints or library views.

• Timing-only fixes that violate power or area budgets.

• Skipping equivalence checks after structural changes.

Principal synthesis review addendum

Regression discipline prevents late-stage surprises by enforcing setup/hold, power, and equivalence checks after every ECO wave.

Metric: post-ECO regressions caught, corner coverage, signoff approval latency