# Study Arms

Source: https://sites.veevavault.help/gr/sitevault/ctms/schedule-arms/

**Who can complete this task?**
- Administrators and Site Staff with the Study Schedule Design & Management Extended Permission

## Study Arms

Adding study arms to your study schedule is optional, but powerful. Adding them requires just a few clicks and provides improved data filtering and reporting, easier participant scheduling and tracking, and smarter budget analysis.

Arms are not the branches themselves; they are a tracking tool assigned to a branch that correspond to the different treatment groups in your study. Assigning study arms to branches doesn’t change the actual schedule; they simply provide an additional way to view, sort, and learn from your data.

## Assign and Use Study Arms

Follow the steps below to use study arms.

### Step One: Define the Study Arms

Before you can assign arms, they must be defined in the Study Schedule Overview.

1. Navigate to **Study Schedule \> Overview**.
2. Select **Edit**.
3. For each study arm: 
  - Select **+ Create Arm.**
  - Enter a name for the arm.

4. Select **Save**.

[![Define Arms](/gr/uploads/sitevault/images/help/ctms-define-arms.png) ](/gr/uploads/sitevault/images/help/ctms-define-arms.png)

### Step Two: Assign Arms to Branches

Arm must complete a single, complete path from the start node of a schedule to the end node. Therefore, while a study branch may have one or more arms associated with it, a study arm may not be assigned to more than one branch. Once assigned, arms follow the entire path of the branch.

1. Navigate to **Study Schedule \> Visit Groups**.
2. For each arm to assign: 
  - Select a visit group.
  - Select the appropriate arm.

3. Select **Save**.

[![Assign Arms](/gr/uploads/sitevault/images/help/ctms-assign-arms.png) ](/gr/uploads/sitevault/images/help/ctms-assign-arms.png)

#### Why can’t I assign arms to all visit groups?

There are a few reasons why the Study Arms field may not be visible in the Edit Visit Group drawer.

- If your schedule is linear (i.e. it _does not_ include branches), then all visits groups are assumed to include all study arms.
- If your schedule includes branches, the Study Arm field will only display on the _first_ visit group for that branch. Subsequent visit groups on the same branch will inherit the same Study Arm selection.

## Key Benefits of Assigning Arms

### Participant Tracking & Scheduling

When adding visits for a participant, you can easily filter by Arm to quickly find and add the correct visits/groups for their specific schedule.

The participant’s assigned arm can be found in Participant Details.

[![Participant Detail - Arm](/gr/uploads/sitevault/images/help/ctms-participant-detail-arm.png) ](/gr/uploads/sitevault/images/help/ctms-participant-detail-arm.png)

When adding participant visits, you can specify the arm for easier selection.

[![Participant Visits - Arm](/gr/uploads/sitevault/images/help/ctms-participant-add-visit-arm.png) ](/gr/uploads/sitevault/images/help/ctms-participant-add-visit-arm.png)

### Reporting & Filtering

Arms act as a powerful filter on various tracking and reporting pages, allowing you to run reports and view data specific to a particular study cohort.

[![Arm Reporting](/gr/uploads/sitevault/images/help/ctms-report-arm.png) ](/gr/uploads/sitevault/images/help/ctms-report-arm.png)

### Schedule and Budgeting View Filtering

You can filter schedule and budget views, making it easier to visualize and validate the correct path for a specific arm as well as have more control when budget forecasting.

[![Filter Schedule by Arm](/gr/uploads/sitevault/images/help/ctms-schedule-arm-filters.png) ](/gr/uploads/sitevault/images/help/ctms-schedule-arm-filters.png)