Forward chaining is executed when the value of any of the source properties change.
Backward Chaining mode executes when the target property is referenced. Backward chaining is supported only for declare expressions.
Based on your requirement, we need to choose the Forward or backward chaining. For your example i.e. A=B+C, we need to use forward chaining. when property B and C value changes we need to calculate A value.
Thanks for your reply. But, I have a question here.
Above, you said,
"If values of B and C changes frequently and in future steps you are using A in few places, then better to use backward chaining(ie calculate value of A when ever it is used)." And "If input values are not changing frequently and target property is used frequently in the application then you can go for forward chaining(ie calculate A when ever input changes)."
So, by these two statements, you are suggesting to execute Declare Expression rule as less as possible to improve performance, right? Is my understanding correct?
If yes, then a question. What chaining to go for when if input values are changing frequently and target property is used frequently in the application?