setting global process variable in jbpm 4.2 process definition

I want to set a variables in a process definition for JBPM4 开发者_高级运维 As these variables will be set for all process instances with the same values

To set a variable with name "VAR_NAME" to a value "VAR_VALUE" in every process instance use element variable in the beginning of your jpdl process definition:

<process key="key" name="name" version="1">
  ..
  <variable init-expr="VAR_VALUE" name="VAR_NAME" type="string"/> 
  <start name="start">
    <transition to="first"/>
  </start>
  ..
</process>

after searching for all available options , I found that the best way to set a variable in a process definition through the tag