Explanation¶

Background on the OED standard — what it is, its file structure and the exposure hierarchy. Detailed chapters (import format, asset details, geography & perils, financial terms and reinsurance) are migrated from the standard’s specification documents.

The four input files¶

OED comprises four input files, designed to let users enter data in a manageable way without having to understand the relationships between many underlying tables:

Location (Loc) — the exposed locations and their coverages, characteristics and primary financial terms.
Account (Acc) — accounts and policies, including policy-level financial terms and special conditions.
Reinsurance Info (ReinsInfo) — the reinsurance programme definitions.
Reinsurance Scope (ReinsScope) — what each reinsurance contract applies to.

This trades some duplication for practicality. The full field lists are in the field reference.

The exposure hierarchy¶

OED follows an organisational and financial hierarchy familiar to catastrophe-model users:

Coverage: The lowest level — the specific type of cover: Buildings, Other (e.g. appurtenant structures or motor), Contents, and Business Interruption (time element). Primary financial terms can attach at coverage level, across property damage (PD = Buildings + Other + Contents), or across all coverages.
Location: A site — a group of coverages at one place. Primary financial terms and facultative reinsurance can attach here. A single location record can represent several buildings (NumberOfBuildings), and related locations can be linked (LocGroup).
Policy: A financial structure applying to a set of locations. Multiple policies can exist under the same account and apply to the same locations (e.g. insurance layers). Within a policy, a special condition applies sub-limits/sub-deductibles to a subset of locations. Reinsurance can attach at policy level.
Account: Groups policies and locations — you cannot have a policy without a location, or a location without a policy. Primary and reinsurance terms can attach here.
Account group: A grouping of accounts for reporting purposes, defined through AccGroup (for example, a binder). No financial structures attach at this level.
Portfolio: A number of accounts, defined through PortNumber. Primary terms cannot attach at portfolio level, but reinsurance structures can.

Which levels financial terms attach to:

Hierarchy level	Defined by	Primary terms?	Reinsurance terms?
Location coverage	Buildings, contents, business interruption, other	Yes	No
Location	`LocNumber`; field names start with `Loc`	Yes	Yes
Location group	`LocGroup`	No	Yes
Policy	`PolNumber`; within it, special conditions (`Cond`) apply first, then standard policy conditions (`Pol`), then layers (`Layer`)	Yes	Yes
Account	`AccNumber`; field names start with `Acc`	Yes	Yes
Account group	`AccGroup`	No	No
Portfolio	`PortNumber`	No	Yes

Because multiple policies can apply to the same locations, take care when summing exposure or ground-up loss at policy level, to avoid overcounting.

Coded values¶

Many OED fields draw on controlled vocabularies (perils, occupancy, construction, country, coverage). Those allowed values are in the coded values reference.

Detailed chapters¶

The full specification narrative, migrated from the OED standard documents: