Evaluation Criteria

When a workflow rule is enabled, the evaluation criteria for that rule is queried each time the corresponding entity is updated or created.

It’s important to ensure the evaluation criteria are set up based on the following rules and order to ensure optimal performance.

1. Order of simplicity: the most simple expression comes first
2. When using AND the least likely expression should be first
3. When using OR the most likely expression should be first
4. Use IsChanged() in “Every time a record is created or edited”
5. Use catch() instead of IsNull() on nested references

Actions

Formula-based Custom Fields

Formula fields will only be calculated when an object is changed, and only when the fields in the formula depend on change.

• In general, Formula fields and workflow rules run at the same speed
  • Optimally, all database columns load prior to execution
  • If an entity was modified concurrently (in a different transaction), a job is triggered
• Formula evaluation criteria needs to be as simple as possible based on the evaluation criteria rules

Rollup Fields

Rollup fields are slower than formula fields or workflow rules but they are calculated inside the project calculation process (i.e. in memory), so their overhead is still small. If you have many of those then you will slow down any update to the project.

• It’s very hard/impossible to implement rollup via workflow rules so you don’t have much choice here
• The Formula and Rollup criteria need to be as simple as possible based on the evaluation criteria rules

Relation summary fields

• Relation Summary fields are the slowest type of custom field
• Runs as a groupable job (outside of the Save transaction)
• Workflow rule may be more efficient in some cases
  For example, if you are implementing Count by referencing additions and deletions of links and just incrementing or decrementing the counter