Triggers and Order of Execution Salesforce

When you save a record with an insert, update,delete or upsert statement. Salesforce perform the following event in below order

1.     Loads the original record from the database or initializes the record for an upsert statement.

2.     Loads the new record field values from the request and overwrites the old values.

If the request came from a standard UI edit page, Salesforce runs system validation to check the record for:

•      Compliance with layout-specific rules
•          Required values at the layout level and field-definition level
•          Valid field formats
•          Maximum field length

Salesforce doesn't perform system validation in this step when the request comes from other sources, such as an Apex application or a SOAP API call.

Salesforce runs user-defined validation rules if multiline items were created, such as quote line items and opportunity line items.

3.     Executes all before triggers.

4.     Runs most system validation steps again, such as verifying that all required fields have a non-null value, and runs any user-defined validation rules. The only system validation that Salesforce doesn't run a second time (when the request comes from a standard UI edit page) is the enforcement of layout-specific rules.

5.     Executes duplicate rules. If the duplicate rule identifies the record as a duplicate and uses the block action, the record is not saved and no further steps, such as after triggers and workflow rules, are taken.

6.     Saves the record to the database, but doesn't commit yet.

7.     Executes all after triggers.

8.     Executes assignment rules.

9.     Executes auto-response rules.

10.  Executes workflow rules.

11.  If there are workflow field updates, updates the record again.

12.  If workflow field updates introduced new duplicate field values, executes duplicate rules again.

13.  If the record was updated with workflow field updates, fires before update triggers and after update triggers one more time (and only one more time), in addition to standard validations. Custom validation rules are not run again.

14.  Executes processes.

Processes are currently available through a private beta program. For information on enabling this feature in your organization, contact Salesforce.

If there are workflow flow triggers, executes the flows.

Flow trigger workflow actions, formerly available in a pilot program, have been superseded by the Process Builder. Organizations that are using flow trigger workflow actions may continue to create and edit them, but flow trigger workflow actions aren’t available for new organizations. For information on enabling the Process Builder (beta) in your organization, contact Salesforce.

15.  Executes escalation rules.

16.  Executes entitlement rules.

17.  If the record contains a roll-up summary field or is part of a cross-object workflow, performs calculations and updates the roll-up summary field in the parent record. Parent record goes through save procedure.

18.  If the parent record is updated, and a grandparent record contains a roll-up summary field or is part of a cross-object workflow, performs calculations and updates the roll-up summary field in the grandparent record. Grandparent record goes through save procedure.

19.  Executes Criteria Based Sharing evaluation.

20.  Commits all DML operations to the database.

21.  Executes post-commit logic, such as sending email.