Can I use global variables in CPM object event handler scripts?

Environment:

Process Designer, Custom Process Model (CPM), Service Process Model (SPM)
All product versions

Resolution:

The use of global variables should be avoided in all scripts used as part of a CPM script.  

Global variables may appear to function in CPMs periodically, and there no assurance that unintended side-effects will not occur as a result.

Variables that are needed should rather be declared in the functions where they are required.