The invention provides a method and system for structuring a procedure for execution in a computer processing environment. The method includes, for example, the step of providing reply-handling logic within the procedure to control execution of the procedure according to a phase parameter. The phase parameter identifies one of a plurality of sub-procedures. The method also includes, for example, the step of identifying within the procedure a call to an external function. A break point is inserted within the procedure at the point of the external function call thereby defining a sub-procedure. The method further includes the step of inserting logic to update the phase parameter.