Workflows cannot perform mathematical operations (add, subtract, multiply, divide) on custom object fields. This prevents automatic calculations like capacity management, inventory tracking, or score aggregation.
USE CASE:
We have an Event custom object with fields:
  • Capacity (total spots available)
  • Registered_Count(current registrations)
  • Available_Spots (calculated: Capacity - Registered_Count)
When an Attendee/Ticket object is created, we need to:
  1. Find the related Event object
  2. Increment Registered_Count by 1
  3. Calculate Available_Spots = Capacity - Registered_Count
  4. If Available_Spots = 0, mark event as full
Current Limitation:
Math operations only work on Contact/Opportunity fields.
Requested Feature:
Please add workflow Math Operation and Array actions for custom objects:
  • Increment Field (add value to numeric field)
  • Decrement Field (subtract value from numeric field)
  • Calculate Field (perform formula: Field_A operator Field_B)
  • Set Field Value (based on calculations from other fields)