Describe the ramifications of field updates and the potential for recursion.
Field updates are actions that can be defined in workflows and approval processes. A field update can trigger other workflows and thus further field updates, as well as escalation rules.
Salesforce processes rules in the following order:
Due to the order of execution, field updates as workflows actions cannot trigger validation, assignment, and auto-response rules. Consequently, field updates can invalidate the data. Furthermore, field updates do not respect field-level permission. They can update fields to which the users triggering the action do not have read or edit access.
Within workflows, field update actions are executed before email alerts, tasks, and outbound messages. However, if there are multiple field updates within the same workflow, the result and order of those field updates are unpredictable.
Between objects in a master-detail relationship, workflows with field updates can be created that update fields on the master object based on changes on the detail object. Such cross-object field updates are supported on custom-to-custom, custom-to-standard, and on few standard-to-standard master-detail relationships.