SD-13.8 — Semantic & Metric Layer

Business Domain: BD-13 Investment Data & Reporting (Cross-cutting — data) · Applies: BOTH

Purpose

Maintains the governed definitions of metrics and the semantic layer over the institution’s investment data — the single, agreed answer to “what does this number mean and how is it calculated.” A figure such as time-weighted return, TVPI, active risk, exposure or AUM is only comparable across the firm if it is defined once; SD-13.8 is the Service Domain that holds that definition. It is the definitional layer: it owns the metric definition, the calculation logic and the certified datasets, but it does not compute the metric in production — BD-09 computes performance, BD-07 computes risk, BD-12 computes accounting figures, each to the definition SD-13.8 governs. One metric, defined once here, computed by whichever domain owns the result.

Service Operations

Metric definition — define each governed metric: its precise meaning, its formula, its inputs, its currency and period conventions, the asset classes it applies to, and any variant forms (gross / net, before / after fees).
Calculation-logic governance — own the documented calculation logic for each metric and the change-control process for it, so a methodology change is deliberate, versioned and propagated.
Semantic-layer maintenance — maintain the business-friendly semantic model over the physical data — the dimensions, the conformed entities, the relationships — that lets reporting and analytics be expressed in business terms rather than physical table structure.
Certified-dataset publication — publish the curated, quality-passed, definition-conformant datasets that the firm’s reporting and analytics are expected to draw on, and mark them as certified.
Metric catalogue and glossary — maintain the catalogue of governed metrics and the business glossary, so any consumer can discover the agreed definition and its owner.
Metric-lineage and dependency management — record which metrics depend on which inputs and on which other metrics, so the effect of a definition change can be traced.
Definition-conflict resolution — adjudicate where two parts of the firm use the same term for different things (or different terms for the same thing) and converge them on one governed definition.

Inputs and outputs

Inputs: the calculation methodologies governed by the computing domains — the SD-09.6 GIPS-governed performance methodology, the risk methodologies of BD-07, the accounting bases of BD-12; the quality-passed data from SD-13.7; the physical data estate.
Outputs: the governed metric definitions, the semantic model and the certified datasets — consumed by SD-13.10 Investment Reporting & Dashboards (which reports to these definitions), by BD-09, BD-07 and BD-12 (which compute to these definitions), and by BD-16’s external-reporting Service Domains (which present figures defined here).

Entities

Owns: E-22 Metric Definition — the governed, versioned definition of a metric (formula, inputs, conventions, variant forms) that stored results reference; plus the semantic model and the certified-dataset register as the broader definitional metadata over the estate. The Metric Definition is the one governance-layer promotion to a first-class entity, because a stored result (E-20 Performance Result, E-19 Risk Measurement) needs to reference it; the data-quality rule, lineage record and certified-dataset register stay Service-Domain artefacts.
Consumes: the full entity model as the physical substrate the semantic layer is built over — E-04 (any book — metric definitions cover both IBOR-basis and ABOR-basis cuts), E-06, E-07 (any method), E-08, E-10 and the rest; the SD-09.6 calculation methodologies governed by the computing domains; the SD-13.7 quality-passed data.
Note: performance, risk and accounting figures are metrics, not entities — OpenIM models the metric definition here in the semantic layer; the stored point-in-time artefacts are E-07 Valuation and E-19 Risk Measurement. BD-09 consumes entities and produces metrics; SD-13.8 is where the metric definition lives.

Standards

GIPS — the performance-metric definitions SD-13.8 governs must conform to GIPS where the firm claims compliance; the methodology is governed jointly with SD-09.6.
ILPA — the private-markets metric definitions (TVPI, DPI, RVPI, PIC) follow ILPA conventions.
DAMA-DMBOK — metadata management and the business-glossary discipline.
The semantic-layer concept is implementation-tooling-neutral in the model; OpenIM specifies the governed definition, not the BI or semantic-layer product that hosts it.

Open extensions

The metric-definition-as-entity question.
The certified-dataset register and the certification workflow to full depth.
The relationship to a stored Performance Result entity (the open SD-09.1 question) — a stored result should reference the metric definition it was computed to.