A code specifying when in the course of an Act a precondition for the Act is evaluated (e.g., before the Act starts for the first time, before every repetition, after each repetition but not before the first, or throughout the entire time of the Act.)
This table controls values for structural elements of the HL7 Reference Information Model. Therefore, it is part of the Normative Ballot for the RIM.
Condition is tested every time before execution of the service (WHILE condition DO service).
Condition is tested at the end of a repeated service execution. The service is repeated only if the condition is true (DO service WHILE condition).
Condition is tested once before the service is executed (IF condition THEN service).
Condition must be true throughout the execution and the service is interrupted (asynchronously) as soon as the condition turns false (asynchronous WHILE loop). The service must be interruptible.
Condition is a loop checkpoint, i.e. it is a step of an activity plan and, if negative causes the containing loop to exit.