Advanced Account Forecasting separates forecast structure into dimensions and measures. Product Code and Product Category define how forecast information must be grouped, so they must be represented as dimensions in the Forecast Fact model. Ordered, shipped, and invoiced quantities are quantitative values and therefore require separate forecast measures.

Salesforce explicitly supports extending the Advanced Account Forecast Fact object with custom dimensions and custom measures. Custom dimensions are added to the forecast fact and then configured as dimension sources and forecast-set dimensions. Custom measures can be implemented as number, currency, or formula fields and included in the forecast set.

Because UC's shipped and invoiced data originates from a custom child object, the DPE processing logic must also be customized so that the required records are extracted, transformed, aggregated at the correct dimensional grain, and written back to the Forecast Fact object. Salesforce recommends cloning and extending the supplied DPE templates rather than modifying the conceptual forecasting model indirectly.

Study Guide references/topics: Configure and Build — Advanced Account Forecasting; Forecast Fact; Custom Dimensions and Measures; Data Processing Engine.