Formula
PDT = PCR_today
− PCR_30_days_agoThresholds
Caution — watch for trend
Declining — act now
Reading it
PCR is a point-in-time snapshot. It tells you where a pillar stands today. PDT is the directional signal — it tells you which way a pillar is moving and how fast. Two pillars at 75% PCR are in the same place. One with PDT of +8 is recovering. The other with PDT of −12 is deteriorating and will reach crisis before PCR alone signals it.
A pillar at 75% PCR with PDT of +8 is not a problem that needs your attention today. A pillar at 88% PCR with PDT of −9 is a problem that is not yet visible in PCR — but will be within two sprints. PDT surfaces that risk before PCR crosses a threshold. That is the gap it fills.
PDT is the early warning PCR cannot provide. Without it, you are looking at a number that tells you where you are. With it, you are looking at a vector that tells you where you are going. Architectural governance that waits for PCR to fall below 70 before acting is reactive. PDT makes it predictive.
How rkito produces it
- 01
PCR computed for current 30-day window
Lens evaluations for the pillar over the most recent 30 days → PCR_today
- 02
PCR computed for prior 30-day window
Lens evaluations for the pillar over the preceding 30 days → PCR_30_days_ago
- 03
Delta = PDT
PDT = PCR_today − PCR_30_days_ago. Positive means improving; negative means declining.
- 04
90-day variant also computed
For pillars with low PR volume, a 90-day window smooths noise and surfaces slower structural shifts.
- 05
No automated chart yet — compute manually
Compare two 30-day windows at /changecontrols/designaudits filtered by Lens pillarId.
Who reads it
PDT tells the VP Eng which architectural domains are in decline before they become crises. A pillar with a healthy PCR but three consecutive negative PDT readings is a domain to watch — not to ignore. PDT converts architectural health from a status report into a risk register.
PDT tells the architect where to direct their attention in the next review cycle. A pillar with stable PCR and flat PDT does not need an architecture review. A pillar with declining PDT does — regardless of where PCR currently sits. PDT prioritizes architect time before it is urgently needed.
How it misleads
What to do at each threshold
Step-by-step response playbook for each signal state.
Pillar conformance is improving or holding. No remediation required.
- Note stability in next architecture review. A positive PDT sustained over two or more sprints is worth surfacing — it signals the pillar is governed and improving.
- No action required. Continue monitoring at the normal review cadence.
Pillar is declining slowly. Observe the trend before escalating.
- Watch for two more review periods. A single yellow PDT reading does not warrant action — it warrants attention.
- If the negative trend persists across two or more consecutive periods, open a Lens review with the pillar owner before PCR crosses into yellow territory.
Pillar is declining sharply. Immediate pillar owner engagement required — but root-cause before prescribing a response.
- Four root causes account for most red PDT readings, and each requires a different response: new team onboarding (awareness gap), new tech stack (Lenses not updated for new patterns), outdated Lenses (now misfiring on legitimate patterns), or genuine architectural drift.
- Do not conflate root causes. An awareness gap needs targeted enablement. Outdated Lenses need a recalibration sprint. Genuine drift needs a structured remediation plan. Treating any one of these as another wastes architect time and erodes trust in the governance system.