Project Variables

Explains how and why to use project variables

What are Project Variables?

Project variables are a special kind of instance variable which has more visibility than a normal instance variable. Project variable values can be searched for, and can be displayed in AquaLogic BPM WorkSpace views.

Note: Project variables were formerly called External variables.

Project variables are used to save information across processes. For example, in ALBPM WorkSpace, you can search for all processes for any instances corresponding to an invoice number.

You can add a new project variable or define an instance variable as a project variable.

A given project variable can be made visible to any process within a Project. To do this, define an instance variable of the same name and type as the project variable in each process which will use it. Then, define a project variable with the same name, and all the instance variables will refer to this project variable.

Once the instance variable has been defined as a project variable, the project variable appears in the Project section of the Variables view.

Any change on that variable has to be done on the Project variable directly and all instance variables that reference to it are automatically updated.

Important: Project Variables are special variables and should be defined thoroughly during the development phase. Once a project variable has been defined and used during user testing or production, the recommendation is not to change its type nor use its name if it has previously been used for one purpose and later on you want to save a different data type.

Restriction: Each project variable requires an additional column in the instance table of the Process Execution Engine database, which means it incurs a performance cost. While there is no set limit, as a rule of thumb fewer than ten project variables are recommended, and in most cases a well-designed project should not require more than about five or six.

Working with Project Variables

Project variables are added from Studio. For detailed instructions see Creating Project and Instance Variables.

Once the variable has been created you can:

Convert the variable to a Business variable
Use the Project variable in the process: an instance variable is created in that process defined as project.

Note: Project variable names may have up to 16 characters.