Lifecycle Decision Mapping

Consolidated reference for mapping forecast lifecycle phases to domain-specific decisions. Each skill references the section relevant to its workflow.

Lifecycle phases are produced by the forecast external engine (see forecast): - emerging — new topic with short-term spike, low historical volume - accelerating — growing across multiple timescales - peaking — short-term deceleration, medium-term still positive - stable — flat across timescales - decaying — declining across timescales

Architecture: Boundary Design

Used by architecture step 0b (Ecosystem Pressure Check).

Lifecycle phase	Boundary recommendation
emerging	Keep boundaries loose — expect interface churn, use Adapter
accelerating	Good adoption window — design against current APIs
peaking / stable	Design for longevity — pin versions confidently
decaying	Wall off behind Facade — minimize coupling surface

Dynamic signals: | Dynamics signal | Architecture implication | |---|---| | reinforcing loop detected | Area is compounding — delaying adoption widens the gap | | dampening detected | Growth arrested — don't over-invest in integration depth | | accumulation detected | Pressure building — define boundary before forced migration |

Design: Pattern Longevity

Used by design step 2b (Pattern Longevity Check).

Lifecycle phase	Pattern guidance
decaying	Adapter/Facade is urgent — isolate the dying dependency, prepare swap interface
accelerating	Lighter wrapping — the API is still finding its shape; heavy abstraction fights upstream changes
stable	Any pattern works — optimize for internal coupling concerns from archobs
emerging	Adapter with narrow surface — expect rapid breaking changes

Compound signal (archobs x forecast): | Archobs signal | Forecast signal | Implication | |---|---|---| | High xnbr + external dependency | decaying | Urgent extraction candidate — the bridge is to a sinking island | | High hubness + external dependency | accelerating | Monitor — high fan-in to a moving target risks cascading breakage | | High leakage between clusters | diverging lifecycles | Split is natural — the ecosystems are pulling apart |

Plan: Risk Amplification

Used by plan step 4b (Risk Amplification).

Archobs signal	Forecast signal	Interpretation	Priority adjustment
High risk (>0.5)	reinforcing loop	Compound risk — structural debt accelerating	Prioritize first
High risk (>0.5)	stable / decaying	Structural debt, stable ecosystem	Schedule normally
High leakage (>0.20)	diverging lifecycles	Boundary spans ecosystems moving in different directions	Prioritize boundary extraction
Low risk	emerging / accelerating	Emerging opportunity	Plan adoption path before coupling grows organically
High coupling to dependency	decaying phase	Dependency is dying — extraction is urgent	Elevate to P0

Spec: Versioning Strategy

Used by spec step 0b (Versioning guidance from forecast).

Lifecycle phase	Versioning strategy
accelerating	Design for version negotiation — expect API churn, use flexible contracts
stable	Pin versions confidently — stable API surface
decaying	Include migration timeline in spec — plan for replacement
emerging	Use narrow contract surface — only pin what you use today