In Workday Adaptive Planning modeled sheets, a value lookup for dimensions or text selector columns serves the primary function of associating specific values to dimension or text fields over time, which are then referenced in formula calculations within the modeled sheet. For example, a value lookup might associate a specific benefit election (e.g., 'Family Plan') with a corresponding rate value that changes over time periods --- enabling the modeled sheet formula to look up the appropriate rate based on the selected dimension value and time period. This lookup mechanism is what powers time-sensitive, dimension-driven calculations in complex planning models such as HR, benefits, compensation, and sales planning. It is not used for entering global assumption values (which is done directly in Assumption accounts), nor for general data entry into model columns, nor for time-spreading functions (which is handled by Splits/Breakback). The value lookup is a purpose-built mechanism for dynamic, time-aware dimensional rate association. Reference: Workday Adaptive Planning --- Modeled Sheets, Value Lookups, Dimension Calculations.