# Start a model in text

Open `project.arcadia`, then choose **Textual model**. The model describes who
reports distress, who assesses it, and the information passing between those
activities. It needs no diagram or handwritten UUIDs.

1. Read each declaration as **kind, alias, display name**. References such as
   `@assess` use the alias. The two allocations state responsibility; the
   interaction states the direction of the exchange.
2. Change `"Assess incident"` to a name suited to your project. Use **Apply all**,
   then **Save all**. Keep the identity clauses added to the accepted source:
   they preserve the same model objects in later edits.
3. Add work and exchanges as your understanding grows. Behavior coverage checks
   identify activities and exchanges that still need process or scenario context;
   these advisory checks allow you to save the intermediate model.

Changing a display name keeps references intact. Changing an alias requires
updating every `@alias` use. Nesting expresses decomposition; an allocation
expresses who performs work. Neither implies the other.

For a larger example with behavior, ports, views and OA/SA correspondence, use
[the water-pressure walkthrough](../release1/README.md). The
[language reference](../../docs/language.rst) defines all declarations and the
rules for splitting a project into included files.