JinJin48

SAP Consultant | BTP · S/4HANA · US Global Rollout

June 27, 2026 · 14 min read

SAP PS WBS Element (AuC)

The WBS Element for Assets under Construction (AuC) is the investment-project-specific variant of the WBS Element that bridges SAP Project System (PS) and Fixed Asset Accounting (FI-AA). While a standard WBS Element collects project costs for operational reporting and settlement to cost centers or G/L accounts, the AuC WBS Element routes those costs through an Asset under Construction object in the asset ledger — enabling capital expenditure tracking, depreciation staging, and eventual capitalization to a productive Fixed Asset. It is optional in the PS master data hierarchy but mandatory in any investment project where fixed asset creation is the end goal. The rest of this article covers its prerequisites, AuC WBS types and constraints, settlement flow architecture, and every field that PS and FI consultants must configure together.

Part 1: WBS Element (AuC) — Core Concepts (All Modules)#

1.1 What Is the WBS Element (AuC)?#

The WBS Element (AuC) is a WBS Element configured to collect investment project costs and settle them into the FI-AA module as an Asset under Construction (AuC). The AuC is an asset class in FI-AA that accumulates costs without depreciation during the construction or development period; at project completion (or at year-end in line-item settlement), the AuC balance is transferred to a final productive Fixed Asset and depreciation begins. The AuC WBS Element is the PS-side gateway for this flow.

1.2 AuC WBS Element Variants and Constraints#

The AuC WBS Element has fewer type variants than a standard WBS Element, but the settlement method and the AuC asset structure choices carry significant downstream impact on asset accounting. Getting these decisions wrong at blueprint stage causes asset reclassification work at project close.

Design principle: Choose the settlement method (summary vs. line-item) in the blueprint phase — it cannot be changed after actual postings are made. For complex investment projects with multiple asset categories, line-item settlement provides audit traceability that summary settlement cannot.

1.3 Organizational Levels and Data Hierarchy#

Data hierarchy with a concrete example

Controlling Area 1000
   │
   └── Project Definition PROJ-2026-001
          Plant Expansion — Line 3 Capacity Increase
          Type: Investment (01)
          │
          ├── WBS Element PROJ-2026-001.2 (Regular)
          │      Engineering & Design
          │      ── settles to ──> Cost Center 4100-CONSTR
          │      No FI-AA capitalization
          │
          └── WBS Element PROJ-2026-001.1 (AuC)
                 Civil Works
                 ── settles to ──> AuC Asset 900001234 (FI-AA)
                                       Asset Class 4000, Company Code 1000
                                       ── capitalized to ──> Final Asset 100005678
                                                                 Building — Line 3 Expansion
                                                                 Asset Class 1100

1.4 Integration with Other Master Data Objects#

The AuC WBS Element sits at the intersection of three functional modules. Its integration scope is deeper and more cross-module than a standard WBS Element, requiring close collaboration between PS, FI-AA, and CO consultants.

Part 2: PS-Specific Field Details#

2.0 Scope of PS Ownership#

Legend: ◎ = Owner / Critical, ○ = Direct involvement

2.1 Basic Data#

The Basic Data fields of an AuC WBS Element are structurally identical to those of a standard WBS Element — the AuC behavior is activated by the Investment Profile and Settlement Rule, not by a separate master data type switch. All standard WBS naming conventions apply.

2.2 Investment and Settlement Data#

Investment and Settlement Data is the functional core of the AuC WBS Element. These fields activate the FI-AA linkage and define the settlement flow. Errors in this section are the most common root cause of failed settlement runs and incorrect asset capitalization.

2.3 AuC Asset Assignment#

The AuC Asset Assignment section captures the FI-AA attributes of the Asset under Construction that the WBS Element settles into. While these fields are maintained in FI-AA (via AS01 or AS02), PS consultants must confirm them during the settlement rule setup to avoid organizational mismatches that block settlement posting.

2.4 Dates#

The AuC WBS Element carries the same set of Basic, Forecast, and Actual dates as a standard WBS Element, with one additional business significance: the Actual End Date (or Technical Completion date) drives the timing of the final capitalization settlement from AuC to the productive Fixed Asset. PS and FI-AA teams must agree on the TECO and AIBU timing during the period-end closing calendar.

What to Read Next#

L1) Big Picture

L2-A) Master Data

L2-B) Transaction