PPM Data Model Overview
The PPM data model is built around four core concepts — Projects, Work Items, Milestones, and Baselines — with work items connected to each other through parent–child hierarchy, links, and dependencies. Understanding how these relate is the key to understanding how Raytio's project tracking works.
The big picture
Projects
A Project is the top-level organisational unit. A work item can belong to a project, but this is optional — standalone and cross-project work items are also supported. Projects carry metadata that applies to the entire body of work:
- Project manager — the user responsible for delivery
- Working calendar and hours — used for scheduling calculations
- Budget fields — reserved for future cost-tracking features
- Auto-generated key prefix — each project has a short key (e.g.
WEB) used to generate human-readable work item identifiers likeWEB-42
For more detail on project metadata and membership, see Projects.
Work Items
Work Items are the central table of the PPM model. Epics, issues, tasks, bugs, and sub-tasks are all stored in a single table, distinguished by a type column. This "unified work item" approach is explained in detail in Unified Work Items.
Each work item optionally belongs to a project and optionally has a parent work item, forming a tree structure. A work item without a project is a standalone item, useful for cross-project or tenant-wide work. Work items can also be connected to each other through links (qualitative relationships like blocks or duplicates) and dependencies (scheduling relationships). For a full explanation of the three relationship types and when to use each, see Hierarchy, Links, and Dependencies.
Work items have:
- Status — a per-project, per-type status value (e.g. Open, In Progress, Done)
- Status category — a derived classification (To Do, In Progress, Done) that enables consistent reporting across projects with different status names
- Priority and dates — standard project management attributes
- Assignees — zero or more users linked to the work item with a role such as Assignee, Reviewer, or Reporter
- Confidential flag — restricts visibility to specific users (see Confidentiality)
Milestones
A Milestone is a named target date within a project. Work items can be assigned to a milestone to group them into a release, sprint, or delivery phase. Milestones belong to a single project and have a title, description, start date, and due date.
Milestones are not work items — they are lightweight markers that work items point to. This keeps the milestone concept simple and avoids conflating "a target date" with "a piece of work to be done."
Links and Dependencies
Work items can be connected to each other in two ways beyond parent–child hierarchy:
- Links are qualitative relationships between two work items (e.g. blocks, relates to, duplicates). They record how items are related without affecting scheduling.
- Dependencies are scheduling relationships between two work items. They have a type (finish-to-start, start-to-start, finish-to-finish, or start-to-finish) and an optional lag, and drive schedule calculations.
Both links and dependencies can cross project boundaries within the same tenant. See Hierarchy, Links, and Dependencies for the full details.
Baselines
A Baseline is a point-in-time snapshot of a project's plan. When a project manager creates a baseline, the system copies the current state of every work item (dates, status, effort estimates) into baseline items. Comparing the current state against a baseline reveals schedule drift and scope changes.
Each project can have multiple baselines, and one can be marked as the active baseline for comparison purposes.
Supporting entities
Beyond the five core concepts, several supporting tables round out the model:
| Entity | Purpose |
|---|---|
| Project Member | Links a user to a project with a specific role (see Role Hierarchy) |
| PPM Category | Project-scoped structured classification (see Labels vs Categories) |
| Label | Tenant-wide free-form tags that can be applied to work items |
| Work Item Assignee | Links a user to a work item with a role (Assignee, Reviewer, Reporter) |
| Activity | Event stream on a work item — comments, status changes, assignment changes, and system events |
| Link | Qualitative relationship between two work items (see Hierarchy, Links, and Dependencies) |
| Dependency | Scheduling relationship between two work items (see Hierarchy, Links, and Dependencies) |
| External Reference | Links a work item to a record in an external system |
Multi-tenancy
The entire PPM model is tenant-scoped. Every project belongs to a tenant, and access controls ensure that users only see data belonging to their own tenant. Within a tenant, project-level membership and the confidential flag provide further access control.