Here are the main limitations to using business rules from Microsoft official materials:
- Business rules run only when the form loads and when field values change. They do not run when a record is saved, unless the scope for the rule is set at an entity level.
- Business rules work only with fields. If you need to interact with other visible elements, such as tabs and sections, within the form you need use form scripts.
- When you set a field value by using a business rule, any OnChange event handlers for that field will not run. This is to reduce the potential for a circular reference, which could lead to an infinite loop.
- If a business rule references a field that is not present on a form, the rule will simply not run. There will be no error message.
- Whole Number fields that use the formats for TimeZone, Duration, or Language will not appear in the rule editor for the conditions or actions, so they cannot be used with business rules.
- For Microsoft Dynamics CRM for tablets, the definition of the business rules are downloaded and cached when CRM for tablets opens. Changes made to business rules are not applied until CRM for tablets is closed and re-opened.
- When you set the value of a lookup field, the text of the primary field value that is set in the form will always match the text that is visible in the rule definition. If the text representing the primary field value of the record you are setting in the lookup changes, the value set by your rule will continue to use the text portion of the primary field value defined by the rule. To fix this, update the rule definition to use the current primary name field value.