Take this line item of a given Service Order for example.
The highlighted fields are distributed within different tables in the backend.
Item No.: CRMD_ORDERADM_I-NUMBER_INT
Product ID: CRMD_ORDERADM_I-ORDERED_PROD
Product( Description 😞 CRMD_ORDERADM_I-DESCRIPTION

Item Category: CRMD_ORDERADM_I-ITM_TYPE

How this item category is determined?
The involved product has item category group NORM maintained:
And in item category determination customizing, it is configured that Transaction type SRVO plus item category group NORM will determine out Item category SRVS.
Quantity: this field is not stored in CRMD_ORDERADM_I any more, but in CRMD_SCHEDLIN.
The field unit together with gross weight and net weight are stored in CRMD_PRODUCT_I instead.
In product master maintenance view it is maintained as 1 ST = 50 KG in gross weight and 40 KG in net weight, this is the reason why you see 50 and 40 in CRMD_PRODUCT_I accordingly since quantity maintained in schedule line is 1 ST.
When the quantity is changed in SCHEDLIN component, it will publish a quantity change event:
And event callback CRM_PRODUCT_I_A_CHANGE_QUAN_EC which is registered to this event will be called to react accordingly.
Say if I change the quantity from 1 to 2, the new value for gross weight and net weight will be re-calculated accordingly: