Define the lifespan projection and confidence model #4

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2026-08-31T08:03:03Z

xavierk commented

2026-08-31 08:03:03 +00:00

Parent map: Chart Fenris’s persistent TUI monitoring redesign

Question

What exact algorithm and user-facing contract should compute the usage-adjusted theoretical lifespan and projection confidence from persisted observations? Decide endurance-source precedence, treatment of active, idle, powered-off, disabled, and unknown hours, recency weighting, habit-change detection, minimum evidence, uncertainty behavior, confidence factors, and language that distinguishes endurance projection from hardware-failure prediction.

Parent map: [Chart Fenris’s persistent TUI monitoring redesign](https://git.bongbetic.com/xavierk/Fenris/issues/1) ## Question What exact algorithm and user-facing contract should compute the usage-adjusted theoretical lifespan and projection confidence from persisted observations? Decide endurance-source precedence, treatment of active, idle, powered-off, disabled, and unknown hours, recency weighting, habit-change detection, minimum evidence, uncertainty behavior, confidence factors, and language that distinguishes endurance projection from hardware-failure prediction.

xavierk added this to the Wayfinder: Fenris persistent TUI monitoring redesign milestone 2026-08-31 08:03:03 +00:00

xavierk added the wayfinder:grilling label 2026-08-31 08:03:03 +00:00

xavierk added a new dependency 2026-08-31 08:03:19 +00:00

#2 Define the persistent observation store and legacy migration

xavierk added a new dependency 2026-08-31 08:03:19 +00:00

#3 Prototype the TUI information architecture

xavierk referenced this issue

2026-08-31 09:18:51 +00:00

Define the persistent observation store and legacy migration #2

xavierk self-assigned this 2026-08-31 09:40:59 +00:00

xavierk commented

2026-08-31 10:09:09 +00:00

Resolution

The projection model is specified as ADR 0002. One usage-adjusted theoretical lifespan from the precedence-chosen endurance baseline; Percentage Used demoted to context (the PU-slope regression and capacity×600 synthesis are dropped).

Headline rate: most recent sustained regime (default full history, capped 90 days); habit change = 7-day mean ≥2×/≤0.5× the prior 28-day mean for 3 consecutive days, auto-adopted and labeled; regimes younger than 7 days cap confidence at Limited.
Hour classification: powered-off (POH delta <90% of wall span), active (≥256 MiB DUW/hour), idle, unknown; disabled time is not an hour state and is excluded from numerator and denominator; unexplained gaps stay in the denominator as unknown seconds and reduce coverage.
Evidence gates: Warming up until 14 distinct UTC day aggregates with ≤2 below 50% coverage; Supported requires verified baseline, coverage ≥80%, freshness <48h, 7/28/90 rates within a factor of 2, no day ≥50% of trailing 28-day bytes, regime ≥7 days.
Confidence: four categorical states always shown with contributing facts; scenario range (7/28/90) instead of any statistical interval; zero rate → "no finite projection from this history"; PU-implied baseline needs ≥2 wear increments; identity change quarantines history, DUW decrease re-warms within the same drive.
Language: the endurance research's required wording and disclosures adopted verbatim; thresholds are hardcoded named constants.

Glossary terms added: sustained regime, habit change, scenario range, coverage (commit 43467f8).

Newly surfaced: the controller-identity key that segments history, and endurance-baseline provenance validation — both ticketed.

## Resolution The projection model is specified as [ADR 0002](https://git.bongbetic.com/xavierk/Fenris/src/commit/43467f8/docs/adr/0002-projection-model-sustained-regime.md). One usage-adjusted theoretical lifespan from the precedence-chosen endurance baseline; Percentage Used demoted to context (the PU-slope regression and capacity×600 synthesis are dropped). - **Headline rate**: most recent sustained regime (default full history, capped 90 days); habit change = 7-day mean ≥2×/≤0.5× the prior 28-day mean for 3 consecutive days, auto-adopted and labeled; regimes younger than 7 days cap confidence at Limited. - **Hour classification**: powered-off (POH delta <90% of wall span), active (≥256 MiB DUW/hour), idle, unknown; disabled time is not an hour state and is excluded from numerator and denominator; unexplained gaps stay in the denominator as unknown seconds and reduce coverage. - **Evidence gates**: Warming up until 14 distinct UTC day aggregates with ≤2 below 50% coverage; Supported requires verified baseline, coverage ≥80%, freshness <48h, 7/28/90 rates within a factor of 2, no day ≥50% of trailing 28-day bytes, regime ≥7 days. - **Confidence**: four categorical states always shown with contributing facts; scenario range (7/28/90) instead of any statistical interval; zero rate → "no finite projection from this history"; PU-implied baseline needs ≥2 wear increments; identity change quarantines history, DUW decrease re-warms within the same drive. - **Language**: the endurance research's required wording and disclosures adopted verbatim; thresholds are hardcoded named constants. Glossary terms added: sustained regime, habit change, scenario range, coverage (commit 43467f8). Newly surfaced: the controller-identity key that segments history, and endurance-baseline provenance validation — both ticketed.

xavierk closed this issue

2026-08-31 10:09:10 +00:00

xavierk referenced this issue

2026-08-31 10:09:47 +00:00

Chart Fenris’s persistent TUI monitoring redesign #1

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