Master variables can be set once and used across all Process Definitions.  

For example, if customerID is used in every definition, instead of defining the variable for each definition, customerID can be set using the master variable screen. Once the variable is defined in the master variables, each new definition will automatically include the “customerID” variable. 

Take a look at the simple master variable UI, designed to make defining variables easier and more manageable. 

Add "variables and globals" by entering their names and selecting a data type. Remove variables and globals by selecting them from the list. Variables and globals have default values based on their data type. The Process Instances page lets you add and delete variables and globals.

• Variables and globals have '0' for the 'Number' data type
• Variables and globals have ' ' for the 'String' data type
• Variables and globals have 'Current date and time' for the 'Date' data type
• Variables and globals have 'false' for the 'Boolean' data type

In the example below, a list of master variables is defined to be included in each new process definition created from now on.  

Create a new process definition as a sample.

The process definition is created and displayed on the designer's canvas. 

Select Actions > Define Variables to view the “global variables” defined in this definition. 

To remove the master variables, select the item and click the “Remove” button. This variable is not included in new definitions created henceforth, but it continues to exist in definitions that are already included.