--- id: CON-PFM-ELG-002 name: Rule Use feature: FEAT-PFM-ELG-02 product_area: platform module: eligibility revision: 1 status: draft product_intent: confirmed implementation_evidence: observed source_sha: services-platform: ad3f6a6582843008ed0f5a17b131878d15829af1 react-console: baf6dae382d6f41dce976c7f848667ccc37e076f definition: >- A rule use connects one application decision to a shared eligibility expression and records its version choice, inputs and handling of uncertainty. owned_by: MOD-PFM-ELG synonyms: - binding - eligibility binding not_to_be_confused_with: - the rule itself - a decision - a role assignment facets: - name: Declared purpose meaning: >- An application question defines subjects, facts, callers and its default failure treatment. used_for: Checking whether an expression is suitable for the question. - name: Consumer reference meaning: 'Application, purpose, record and readable label locate the use.' used_for: Finding all places affected by an expression change. - name: Version choice meaning: >- Following selects the effective publication; pinning retains a chosen release. used_for: Balancing automatic updates with stable seasonal or audit decisions. - name: Configured parameters meaning: The use supplies values compatible with the expression’s declarations. used_for: Reusing a rule at different thresholds without rewriting it. - name: Uncertainty policy meaning: >- Closed, open with review and defer interpret an indeterminate state differently. used_for: Giving the asking application an explicit failure response. - name: Availability meaning: Active uses accept requests; suspended uses reject them until resumed. used_for: Stopping a broken consumer connection during repair. - name: Evaluation plan meaning: >- A compiled expression and changing version tag support reuse and revalidation. used_for: Detecting changes while concealing internal queries from staff readers. relationships: - to: CON-PFM-ELG-001 statement: >- Each use selects one expression, and a consumer cannot bind twice to that expression. provenance: test source: >- services-platform:modules/eligibility/tests/integration/services/persistence/bindings.integration.spec.js#refuses a second binding of the same consumer to the same definition - to: CON-PFM-ELG-003 statement: >- Evaluation normally enters through a consumer use; author trials are the exception. provenance: observed source: 'services-platform:modules/eligibility/services/evaluate/hosted-evaluate.ts' lifecycle: - state: active meaning: The consumer can obtain evaluation results. how_it_changes: Administrative suspension or a forced incompatible release pauses it. - state: suspended meaning: >- Requests fail explicitly instead of receiving a negative qualification answer. how_it_changes: Resumption is available while the underlying rule is not archived. acted_on_by: - CAP-PFM-ELG-002 - CAP-PFM-ELG-004 - CAP-PFM-ELG-005 - CAP-PFM-ELG-006 - CAP-PFM-ELG-007 - CAP-PFM-ELG-008 - CAP-PFM-ELG-010 visible_to: - ACT-PFM-023 - ACT-PFM-024 evidence: - >- services-platform: docs/eligibility.md, docs/responsibilities.md, docs/attention.md; docs/milestones/PLAT-M11 to PLAT-M18 records and the PLAT-M11, PLAT-M15 and PLAT-M16 plans; docs/proposals/eligibility/17-decision-register.md, docs/proposals/responsibilities-and-attention/16-decisions.md; modules/eligibility/db/eligibility-bindings.table.ts, eligibility-consumer-kinds.table.ts, eligibility-plans.table.ts, binding-fit.ts, services/bindings/consumer-bindings.ts, services/compile/binding-plan.ts. - >- react-console: components/eligibility/embeds/**, components/eligibility/governance/usage-panel.tsx. supersedes: [] --- # Rule Use ## What It Is A rule use describes where an application relies on a qualification definition. The same active-member rule might support a product purchase and a role assignment, but those questions do not necessarily supply the same facts or accept the same uncertainty. The use captures those differences without duplicating the expression. It identifies the application, declared purpose, consumer record and a readable label. Staff can create a use through a product’s eligibility card, or a consumer application can register it through service dispatch. Platform keeps the use separately from the product record. Its own identity allows later updates and decision history to refer to the same consumer relationship. Uniqueness prevents the same consumer from registering the same rule twice. ## What It Is Not A use is neither the qualification expression nor an answer to it. It describes the question’s context and configuration. Changing its inputs does not change other uses of the expression. Even a use for assigning a role remains distinct from the resulting Security holding. The binding-management routes do not establish a separate permission check on the referenced consumer record. ## How It Is Used A manager chooses a shared rule or authors a private expression inside the product card. Platform checks whether the declared purpose can support that expression. Parameters can specialize it, and following or pinning determines how releases affect it. Staff review uses from the rule’s dependency view before publication. During an incident suspension stops requests until the use can be repaired. A changed expression can cease to fit a follower, so release review needs to include dependent uses. ## Its Facets **Declared purpose.** An application question defines subjects, facts, callers and its default failure treatment. Checking whether an expression is suitable for the question. **Consumer reference.** Application, purpose, record and readable label locate the use. Finding all places affected by an expression change. **Version choice.** Following selects the effective publication; pinning retains a chosen release. Balancing automatic updates with stable seasonal or audit decisions. **Configured parameters.** The use supplies values compatible with the expression’s declarations. Reusing a rule at different thresholds without rewriting it. **Uncertainty policy.** Closed, open with review and defer interpret an indeterminate state differently. Giving the asking application an explicit failure response. **Availability.** Active uses accept requests; suspended uses reject them until resumed. Stopping a broken consumer connection during repair. **Evaluation plan.** A compiled expression and changing version tag support reuse and revalidation. Detecting changes while concealing internal queries from staff readers. ## How It Relates The use belongs to one eligibility rule and supplies the policy applied to its evaluation. Recorded decisions preserve this connection even after the use is removed. Application purpose declarations provide the subjects, caller types and evaluation mode used in compatibility checks. Security and Commerce own their resulting business behavior; Platform owns the shared record of the connection. ## What It Could Become The product should reconcile the intended consumer-record permission boundary with the current binding routes. Additional editor cards can reuse this connection model, but their presence should be verified within their owning modules. Consumer-process evaluation also needs a published interface. Cache behavior deserves clear guidance: suspension refuses immediately, while resuming an unchanged plan can reuse an earlier display answer.