Granularity is the level of detail chosen for representing data. In demand forecasting, that choice is also a product decision: finer records may support richer use cases, while coarser records can reduce computation without hurting performance. section 9.4.1
Daily versus weekly demand data
Representing demand by day, store, and item creates a more granular dataset. Aggregating to week, store, and item reduces required computations by a factor of seven, while performance may remain unchanged or improve. The choice should be checked with product managers, category managers, users, and other stakeholders because it reshapes the stock management system’s possible uses. section 9.4.1
