Purpose

Admins may want to disable "Board" button from the top navigation bar even though they are using Jira Software Application. These are the steps to achieve that. 

Solution

• Go to ⚙ > Manage Apps
• Click Manage Apps on the left-side menu.
• Look for Jira Agile, and choose All apps:
  
• Collapse the list of module, look for Planning Board Menu Item and click Disable:
  
• Refresh the page.
• The Board button will no longer show on the top navigation bar: