The onboarding process starts with initiating onboarding and ends with the new hire getting converted into an employee (internal user). After onboarding is initiated, the hiring manager collects the new hire information, reviews the new hire data, and adds new hire tasks. Upon completing these tasks, the new hire gains access to the Your Onboarding Checklist page, from which they perform the tasks assigned by the manager by selecting the respective cards displayed in the To-Do section of the home page.
Onboarding processes can be initiated in two ways:
Through an Applicant Tracking System (ATS), such as SAP SuccessFactors Recruiting
By adding the new hire directly (or manually) into SAP SuccessFactors Onboarding

Most companies favor integrated systems for managing various processes. As a result, starting the onboarding process from an ATS is more common than manually adding new hires directly into Onboarding.
Automatically Initiating Onboarding in SAP SuccessFactors Recruiting

The onboarding process can be automatically initiated from within SAP SuccessFactors Recruiting.
Administrators can select the Enable Automatic Initiation for Onboarding checkbox on the Onboarding Integration Setup page and configure a specific business rule to automatically initiate the onboarding process. Selecting this option will automatically initiate onboarding for all job requisitions that meet the onboarding initiation eligibility criteria defined.
Depending on your business requirement, you can opt to use a combination of automatic and manual onboarding initiation.
For details on the configuration, please refer to the SAP SuccessFactors Onboarding Implementation Guide: SAP SuccessFactors Onboarding | SAP Help Portal.