Order (item) has no material

What causes this issue?

The settings in Customizing require the <DS:GLOS.target_costs>target
costs</>, <DS:GLOS.work_in_process>work in process</>, and/or scrap for
the order to be calculated using a particular cost estimate. This cost
estimate is normally assigned to the material entered in the order.
However, the order entered does not have any materials. This means that
the system could not calculate target costs, WIP, or scrap for it.

System Response

Because no target costs were calculated, the system could not calculate
any variances.

How to fix this error?

Check your entries.

Error message extract from SAP system. Copyright SAP SE.