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It has taken many years of experiments and discussion to come up with the Instruction and Action classes to support workflow. These classes allow statements, using the action class, to be made when acting on an instruction that refer to the instruction but do not alter it. The state of the activity in the instruction is actually derived from the sum of action statements made with reference to that activity. The result is that a medication administration may leave the state of a medication order as 'active' or 'completed'. A decision not to administer a medication may leave the state of the medication order as 'cancelled' (if not started), 'suspended' or 'aborted' if not started. An action such as withheld may even leave the instruction as active.
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