Designers sometimes encounter numeric values that don’t clearly fall into either the fact or dimension attribute categories. A classic example is a product’s standard list price. If the numeric value is used primarily for calculation purposes, it likely belongs in the fact table. If a stable numeric value is used predominantly for filtering and grouping, it should be treated as a dimension attribute; the discrete numeric values can be supplemented with value band attributes (such as $0-50). In some cases, it is useful to model the numeric value as both a fact and dimension attribute, such as a quantitative on-time delivery metric and qualitative textual descriptor.