# ListRoutingsByItem

## Overview

ListRoutingsByItem lists routing revisions available for one produced item and scope so planners can choose or compare executable process definitions.

## Business Rules

- Company scope and parent item reference are required.
- Optional filters may restrict by site or status.
- Results include all statuses by default.
- Results are ordered by revision or effectivity precedence.

## Process Flow

```mermaid
flowchart TD
    A[Receive company, item, and filters] --> B[Query routings for item and scope]
    B --> C[Apply optional site and status filters]
    C --> D[Order routing revisions]
    D --> E[Return routing list]
```

## External Dependencies

- None

## Error Scenarios

- **COMPANY_SCOPE_REQUIRED**: Company scope was not provided
- **PARENT_ITEM_REQUIRED**: Parent item reference was not provided.

## Test Cases

- lists routing revisions for a produced item
- filters routing revisions by site when provided
- filters routing revisions by status when provided
- returns all statuses by default
- returns an empty list when no routings exist
- returns routing revisions for the requested company scope
- returns error when the parent item reference is missing
- returns error when company scope is missing
