Salesforce: Assign using active assignment rule

In Case and Lead, the Salesforce admin can configure Assignment Rules to automatically assign a newly created Lead or Case to a specific User or Queue. This assignment rule will trigger upon the case or lead creation, regardless of how the case or lead is created. 

The rule will also run when editing the case or lead by clicking the Edit button, however, it will not run by clicking the pencil icon on a field (vote this idea) or edit from API (such as Workbench), so this rule is ideal only for manual record creation from Salesforce web user interface.

If necessary, you can set the "Assign using active assignment rule" checkbox visible, this will allow your users to manually enable or disable the assignment rule, the "Assign using active assignment rule" checkbox will be visible on creating or editing the record (from Edit button).

Lead

 Case

How to configured?

Go to Setup | Object Manager | Leads or Cases | Page Layouts, then click the Layout Properties button, then enable Default.

Case page layout

Lead layout properties

Case layout properties

Once you have the assignment rule configured, the best practice is to hide that checkbox "Assign using active assignment rule", so the rule will always run. Although in some scenarios, even if you want to let the checkbox visible, set the Default enabled by default. This checkbox is located at the far bottom of the record page, so some users may not even notice it.

How to hide the checkbox "Assign using active assignment rule"?

Untick "Show on edit page" in the page layout properties. Even the checkbox is not shown, the assignment rule will work as configured, as long as the Default in the Lead or Case Assignment Checkbox is enabled in the layout properties

Reference:

• Assignment Rules
• 'Assign using active assignment rules' checkbox always checked by default
• Why Salesforce assignment rule is not working?
• Case Assignment Rules not working
• Idea Exchange: Assignment rules don't work with Inline Edits