COSS table — COSS Table for CO Secondary Cost Totals

One row in COSS represents the totalled value of postings for a single combination of CO object, fiscal year, value type, version, secondary cost element (or statistical key figure) and origin, with the twelve or more posting periods of that year carried as separate value columns on the same row rather than as separate rows. COSS is restricted to secondary cost elements (allocations, internal activity, settlement, order-to-order transfers) and statistical key figures; primary cost element totals for the same objects sit in the parallel table COSP. Neither table stores the underlying document; the totals are maintained as postings happen and the individual documents that built them up sit in the CO line item table COEP.

COSS is client-dependent and large, so MANDT is implicit and every other selection matters. Restrict on GJAHR and WRTTP first; pulling actual and plan together in one unfiltered read produces meaningless combined totals. OBJNR is not human-readable and cannot be filtered with a wildcard on a cost center or order number directly, it has to be resolved through the relevant master table first (CSKS for cost centers, the order or project master for orders and WBS elements). Do not run a broad KSTAR-only selection across all controlling areas; cost element numbering is not unique across controlling areas the way it looks.

Symptom: a cost center shows an actual cost that nobody can explain from direct postings. Resolve the cost center to its OBJNR via the cost center master, then select COSS for that OBJNR, the fiscal year in question, and the actual value type. The KSTAR returned is the secondary cost element that received the posting, and VRGNG shows what kind of CO transaction produced it, typically an allocation cycle or a settlement run. The period value field for the period in question confirms the amount, and COEP for the same key gives the originating document.

In S/4HANA the universal journal in ACDOCA is the system of record for financial and much of the controlling detail, but COSS has generally continued to be updated for secondary cost postings and statistical key figures rather than being retired outright, because these object types are not represented in ACDOCA the same way FI-relevant primary costs are. Consultants should not assume COSS is a dead or purely historical table on an S/4HANA system; it is worth confirming on the specific release and configuration in front of them whether it is still actively written before deciding a reconciliation approach.

A discrepancy traced to COSS is a controlling question, owned by whoever runs cost center accounting, internal orders, or project controlling, not by FI accounts payable or receivable teams. Extraction or reporting issues against the table are an ABAP or BW/analytics concern once the controlling team has confirmed which object, period and value type are in question.

COSP is the parallel totals table for primary cost elements and is checked alongside COSS as a matter of routine. COEP holds the individual CO line items that COSS summarizes and is where a specific document is found once the totals row points to the right object and period. CSKS, CSKA, CSKB and CSKT supply the cost center and cost element master data needed to decode OBJNR and KSTAR. Allocation cycles, order settlement, and periodic repostings are the transactions that actually write to COSS.