###### Add a lookup matrix

A lookup matrix serves as a source for logic-based calculations in lookup matrix type calculated fields.

To add a logic-based calculated field to an item, you must first add the lookup matrix and give it a name. Adding an optional description defines how the lookup matrix is used in calculated fields.

To configure a lookup matrix, you must select a pick list for the matrix columns, rows, and results.

**To add a lookup matrix:**

Create pick lists for the calculation inputs (matrix rows and matrix columns) and the calculation results (matrix values).

Select

**Lookup matrix**as the pick list type.(Optional) To change the table color from default gray, select a row in the Pick list values table, select

**Edit values**, and select a color.

Select

**Admin > Organization > Lookup matrices**.Select

**Add lookup matrix**.Enter a name and optional description for the lookup matrix.

Configure the lookup matrix settings:

Under Matrix Configurations, use the drop-down selectors to configure the matrix columns, rows, and values/result.

Select

**Generate matrix**, then select matrix values for each matrix cell according to the logic-based calculation outcomes you need.For example, when you select

**Low**for the P-total field and**Minor**for the Severity field, the calculated field for Risk Score returns the result**Acceptable**in yellow.

Select

**Save & done**.Select from an existing item type or add a new item type, then select

**Add field**.Confirm that the calculation input fields were added to the item: make sure the pick lists match the configuration pick lists used for the calculation lookup matrix source you want.

In the Add field window that opens, select

**Lookup matrix**as the calculation type.Select from an existing lookup matrix as the calculation source, then select from available fields as calculation inputs.

Select

**Save**.