The standard model cookbook
The standard model has many entities, and a raw relationship diagram makes them look like a tangle. This cookbook reads the other way round: start from a real customer, watch entities appear only as the story needs them, and see exactly which id links each one to the next. Start with the two ideas below, then dive into a section.
Four ideas that explain everything
One flat State, not a tree
Every entity — parties, financing, assets, collateral, incomes — is a top-level array on State. Nothing nests inside anything else.
Entities link by id reference
One entity stores another’s id. A collateral object holds an assetId; a deed lists the loan ids it secures. Follow the ids and the picture stitches itself together.
People attach through Roles
A person is never stored inside a loan or a house. A Role {partyId, role, share} links them — OWNER of an asset, DEBTOR on a loan, MORTGAGOR on a deed.
Today vs. if-approved
What the customer has today lives on the root arrays. What they are applying for lives in changes[], grouped by a scenario.
State + Scenario = a potential future
An application never edits the customer’s current picture. It proposes a future — a set of changes grouped into a scenario — and the engine evaluates that future against today’s state.
State is the present
The root arrays — assets, financing, incomes, collateralAgreements — describe what the customer owns, owes and earns today. Nothing here is hypothetical.
Changes are deltas
A Change in state.changes[] is one edit on top of the present. CREATE_ELEMENT introduces something new; every other kind modifies or removes an existing element and points at it with basicChangeInformation.parentId.
A Scenario groups them
A Scenario is a named future: it lists the changes[] that belong together, plus the decisions[] and affordability analysis computed for that combination. State + scenario = a potential future.
Five sections
Read them in order, or jump to what you need.
People & households
Parties, the Case, households and roles — how the model holds the applicants and links them to everything by id.
Entities & the security chain
The flat entity model and the one relationship to learn first — how a loan, deed, collateral object and home link by id.
Scenarios & changes
How an application proposes a future: changes[] grouped into a scenario, every change kind, and worked examples.
Money & affordability
Why one application produces many analyses: baseline vs scenario, the period series, and the key figures the decision reads.
Decisions & resolvers
The four decision kinds, what GREEN / YELLOW / BLUE / RED mean, and how the resolver chain settles a hit.