Valuation grouping code is used to group the valuation area, In SAP, we can have valuation level at Company code level or at plant level. General practice is to use the valuation area at plant level, because valuation may differ from one plant to another. The valuation grouping code makes it easier to set automatic account determination. If we need to define common account determination for several valuation areas, we can assign same valuation grouping code to all those valuation areas. We can maintain the valuation group code in OMWD for various valuation areas.