# Concepts

The core objects Throughline is built from. Everything in the product is one
of these, or a relationship between two of them.

## Productions

A **production** is a show. A feature, a season of television, a
commercial — one production per thing you're making. An episodic series is
still a single production: its episodes live underneath it rather than each
getting their own, so the graph, the crew list, and the budget stay whole
across the season instead of splitting at episode boundaries.

## Departments

A production is organized into **departments** — Props, Camera, Editorial,
VFX, and so on. Each department has its own view: the assets it owns, the
people on it, the approvals waiting on it, and the deliveries moving in and
out. Departments are also the unit most permissions are scoped to — what a
crew member can see is usually a function of which department they're on.

## The production graph

Underneath the app is a single **graph**: scenes, characters, locations,
props, and every other asset, connected to the departments that own them and
the scenes they appear in. A schedule change, a script revision, or a new
asset version is a change to this same graph — not a copy of it living in a
spreadsheet somewhere — which is what keeps the rest of the product in sync
without anyone re-entering the same fact twice.

## Approvals

An **approval** is a structured decision chain — who has to sign off on
something, in what order, and what happens when they do (or ask for
changes). Approvals gate the things that shouldn't move without a person
accountable for them: a locked cut, a hero prop build, a delivery going out
the door.

## Budgets and POs

Each department works against its own **budget** envelope, broken down into
line items and tracked against actual spend. **Purchase orders** are how
committed spend gets recorded against a line before it shows up as an
invoice — so the budget picture reflects what's already promised, not just
what's already paid.

## Call sheets and day-outs

**Call sheets** are the day's shooting plan — call times, locations, scenes,
who's needed and when — generated from the schedule rather than assembled by
hand. **Day-out-of-days (DOODs)** track which cast and crew are needed on
which shoot days across the whole schedule, so a wardrobe or scheduling
question about "when is this actor working" has one place to look.

## The Assistant

Every department — and the production as a whole — has an **assistant** that
works over the graph. It can answer questions about the state of the show,
draft notes, and, when given the authority to, take action: creating an
asset, moving a step on an approval, filing a note against a scene. It
always acts as the delegate of an accountable person, never as an
independent actor.