How to work with dynamic members in business rule

Hello experts,

I am working with dynamic member in my calculation rule.

Sometimes, the rule calculates as expected, but other times, it fails to execute properly or runs for exceptionally long time.

For example:

"KTB_RC_Calculated"(

                IF("KTB_Direct Input"->"Select Co-Delivery Project"->BegBalance->"No Year"->"No Currency"->"PI Approved Budget" <> #Missing)

                    IF(@ISMBR("Co-Delivery CAPEX"))

                        "KTB_RC_Calculated"  = "No Project Element"->"Current PI Approved Budget"->"Total AppID"->"Total Phases"->"PI Approved Budget"->&LatestApprovedScenario->"Task 1.0"->@CalcMgrSLMember("KTB_Direct Input"->"Select Co-Delivery Project"->BegBalance->"No Year"->"No Currency"->"PI Approved Budget");