# Design

The design of PyTES is recorded in three documents:

- the **design document**, with the decisions and their reasons, what is deferred and what
  is still open;
- the **model contract**, what every model provides (its variables, units, signs and
  parameters), checked by the conformance suite. Where the contract's prose and the tests
  disagree, the tests win;
- the **findings**, the log of every change to the contract and of every discrepancy with a
  reference.

```{toctree}
:maxdepth: 1

DESIGN
contract
findings
```