Oracle Waveset 8.1.1 Deployment Reference

Note about Optimizing Variables Beyond a Single Iteration

XPRESS variables typically persist for only a single iteration over the form fields. As a result, you can use a variable within an Expansion phase but not on a subsequent Derivation phase. If you need a computed value to remain relevant beyond one field iteration, use a hidden form field instead. Hidden field values are stored in the view and will persist until the editing session is either canceled or saved.