PROforma Expressions: Frequently Used Expressions
In this section you will find expression that are frequently used in preconditions, state triggers and postconditions.
Preconditions
Preconditions are typically used in combination with scheduling constraints. Different expressions are characteristic of preconditions, depending on the workflow pattern.
Preconditions Following Decisions
Frequently used expressions: Preconditions following decisions
Exclusive Choice
A point where, based on a decision, one of several tasks is chosen. Preconditions control task activation and typically have the following structure:
Result_of(Decision) = Candidate
Browse through a process-description sample:
- Chronic Cough
- The Scheduling decision is followed by two plans: CXR first and CXR in parallel. Depending on the decision result, one of the plans is activated and the other is discarded.
- If you have installed the Tallis Toolset, you can find this sample in the World > Samples folder in the ACL Web Repository.
Run this sample file- Click here for a detailed description of this sample.
Multi Choice
A point where, based on a decision, a number of tasks are chosen. Preconditions control task activation and typically have the following structure:
Result_set(Decision) includes Candidate
If more than one candidate can trigger task activation, the expression can be structured as follows:
result_set(Decision) = [Candidate1, Candidate2, Candidate3]
Browse through a process-description sample:
- Chronic Cough
- The Cause decision is followed by four plans. One or more of them would be activated, depending on the decision results.
- If you have installed the Tallis Toolset, you can find this sample in the World > Samples folder in the ACL Web Repository.
- Run this sample file
- Click here for a detailed description of this sample.
Preconditions Following Enquiries
Frequently used expressions: Preconditions following enquiries
A point where, based on workflow data, one or more of several tasks are chosen. Preconditions control task activation and typically have the following structure:
Data Item Comparison Operator Value
Browse through a process-description sample:
- Chronic Cough
- The Patient information enquiry is followed by two enquiries: Initial assessment - male patient and Initial assessment - female patient. Depending on the data collected by the Patient information enquiry, one enquiry is activated and the other is discarded.
- If you have installed the Tallis Toolset, you can find this sample in the World > Samples folder in the ACL Web Repository.
- Run this sample file
- Click here for a detailed description of this sample.
State Triggers
Frequently used expressions: State triggers
State triggers are commonly used in dataflow without scheduling constraints. They monitor state and the data changes in the process-description, and typically have the following structure:
Data Item Comparison Operator Value
or one of the following:
- is_completed(Task)
- is_discarded(Task)
- is_dormant(Task)
- is_in_progress(Task)
Browse through a process-description sample:
- Cold And Flu Guide
- The Recommend Vaccine action has a state trigger.
- If you have installed the Tallis Toolset, you can find this sample in the World > Samples folder in the ACL Web Repository.
- Run this sample file
- Click here for a detailed description of this sample.
Postconditions
Frequently used expressions: Postconditions
Assertions that typically take the form:
Data Item = Value
or
Data Item = if(Expression, value_if_true, value_if_false)
Browse through a process-description sample:
- Hypertension
- The Setting BP values action has a postcondition which sets the target systolic and the target diastolic blood pressure values according to the result of the Target BP decision.
- If you have installed the Tallis Toolset, you can find this sample in the World > Samples folder in the ACL Web Repository.
- Run this sample file
- Click here for a detailed description of this sample.