Phase 1: Enterprise Foundation (FI/CO Prerequisites)

Prime Directive Check: Before any IS-U configuration can begin, the standard SAP Financial Accounting (FI) and Controlling (CO) enterprise structure must exist. IS-U is an industry layer built on top of ECC/S4 core — without a Company Code, there is no legal entity to bill from; without a Controlling Area, there is no cost allocation framework.

⚠️ Prerequisite: Phase 0: System Standards & US Localization must be complete. Country settings (date format, decimal notation, currency, tax procedure TAXUSJ) and user defaults must be verified before creating any enterprise objects.

Step 1.1 — Define the Chart of Accounts

SAP Screen Flow

Screen 1 — Chart of Accounts List (Table View)

When you execute OB13, SAP displays the existing Chart of Accounts entries in a table view.

1. Click the New Entries button on the toolbar.

Screen 2 — New Entries: Details

Fill in the following fields:

2. Click Save (💾) or press Ctrl+S.
3. A transport request dialog appears → select or create a Workbench Request → Confirm.

Why This Is Step 1

The Chart of Accounts (CoA) is the most fundamental financial object in SAP. It defines the structure of the General Ledger — every posting, whether it originates from AP, AR, Asset Accounting, or IS-U’s FI-CA, ultimately resolves to a G/L account within this chart. The Company Code (Step 1.3) cannot be created without assigning a CoA.

Key Configuration Notes

• Use 10-digit account numbers to follow S/4HANA best practice and allow granular revenue/expense segmentation for utility rate classes.
• The CoA CAOH is a custom identifier reflecting “Chart of Accounts — Ohio.” SAP delivers standard CoAs (INT, CAUS), but for a regulated utility, a dedicated CoA provides full flexibility to model PUCO-compliant revenue accounts, regulatory asset accounts, and rider-specific liability accounts.

Step 1.1a — Define G/L Account Groups

Account Groups control the number range and field layout of G/L accounts within a Chart of Accounts. Without at least one Account Group defined for CAOH, T-Code FS00 will reject any G/L account creation with the error: “No account groups are defined in chart of accounts CAOH”.

SAP Screen Flow

Screen 1 — Account Groups (Table View)

When you execute OBD4, SAP displays existing account groups.

1. Enter Chart of Accounts CAOH in the header field (or filter).
2. Click New Entries.

Screen 2 — New Entries: Account Group Details

Create the following account groups:

3. Click Save (Ctrl+S).
4. Confirm the transport request.

Why This Step

Account Groups are the structural backbone of the Chart of Accounts. They serve two purposes:

• Number Range Segmentation: They restrict which number ranges are valid for each category of G/L account (e.g., all asset accounts must be in the 1xxxxxxxxx range).

• Field Status Control: Each group can have its own field status rules governing which fields are required, optional, or hidden when a user creates a G/L master record.

• Dependency from Previous Instructions: Requires the Chart of Accounts CAOH from Step 1.1.

• Dependency for Next Instructions: Every G/L account created via FS00 — including the utility revenue and AR accounts needed for FI-CA account determination (Phase 2, Step 2.5) — requires an Account Group to exist first.

Step 1.1b — Define Retained Earnings Account (P&L Account Type)

SAP requires a P&L Statement Account Type and a corresponding Retained Earnings G/L account before any P&L account can be created in the Chart of Accounts. Without this, FS00 will reject revenue/expense account creation with the error: “No P&L statement account type is defined in chart of accounts CAOH”.

SAP Screen Flow

Screen 1 — Retained Earnings Account: Selection

1. Execute OB53 → Enter Chart of Accounts CAOH → click Execute (⏩).

Screen 2 — Retained Earnings Configuration

2. Click New Entries.

3. Click Save (Ctrl+S).

Note: If G/L account 3900000000 does not yet exist, SAP will display a warning — this is expected. The account will be created later via FS00 in Phase 2, Step 2.5 C.3. The OB53 entry simply tells the system where to carry forward P&L balances at year-end closing.

Clarification: OB53 is a one-time, single-entry configuration. You do NOT enter every G/L account here. You only define one mapping: “For P&L account type X, carry the year-end net result to Retained Earnings account 3900000000.” Every revenue/expense account you later create in FS00 is automatically classified as P&L by its Account Group — SAP uses this OB53 mapping at year-end to sweep their balances.

Why This Step

At fiscal year-end, SAP automatically carries the net result of all P&L accounts into a single Balance Sheet account — the Retained Earnings account. This is defined per Chart of Accounts, not per Company Code. Without it:

• No P&L-type G/L account (revenue, expense) can be created in FS00.

• The year-end closing program (FAGLGVTR) cannot execute.

• Dependency from Previous Instructions: Requires the Chart of Accounts CAOH (Step 1.1) and Account Group EQTY (Step 1.1a).

• Dependency for Next Instructions: All revenue accounts (4100000000, 4200000000, 4300000000) created in Phase 2, Step 2.5 C.3 require this configuration.

Step 1.2 — Define the Fiscal Year Variant

SAP Screen Flow

Screen 1 — Fiscal Year Variants (Table View)

When you execute OB29, SAP displays existing Fiscal Year Variants.

1. Click the New Entries button.

Screen 2 — New Entries: Details

2. Click Save (Ctrl+S).
3. Confirm the transport request.

Note: Since Calendar Year is checked, SAP auto-populates the period boundaries (Period 1 = Jan 1–31, Period 2 = Feb 1–28/29, etc.). No manual period assignment is needed.

Why This Is Step 2

The Fiscal Year Variant defines the period structure for all financial postings. It must exist before a Company Code can be created (Company Code references a Fiscal Year Variant). The utility operates on a calendar-year fiscal year (Jan–Dec).

Key Configuration Notes

• 4 special periods are standard for regulated utilities. They accommodate:
  • Period 13: Year-end regulatory adjustments (PUCO rate case true-ups)
  • Period 14: Tax adjustments
  • Period 15: Audit reclassifications
  • Period 16: Final closing entries
• Year-Dependent = unchecked means the same period structure repeats every year (standard for calendar-year entities).

Step 1.3 — Create the Company Code

Part A: Define Company Code Base Data (OX02)

SAP Screen Flow

Screen 1 — Edit Company Code: Initial Screen

When you execute OX02, SAP presents a dialog with options.

1. Click New Entries (or in some versions, the Edit → New Entries menu).

Screen 2 — New Company Code: Details

Fill in the required fields:

2. Click Save (Ctrl+S).
3. Confirm the transport request.

Part B: Maintain Company Code Global Parameters (OBY6)

SAP Screen Flow

Screen 1 — Global Parameters Table

1. Locate Company Code AEP1 and double-click it.

Screen 2 — Company Code Global Data

2. Assign the foundational financial variants created in previous steps:

3. Click Save (Ctrl+S).

Why This Is Step 3

The Company Code is the legal entity in SAP. It is the organizational unit for which a complete, self-contained set of financial statements (balance sheet and P&L) can be drawn. Every IS-U Contract Account, every billing posting, every FI-CA document will be posted under this Company Code.

Key Configuration Notes

• ⚠️ The Company Code ID AEP1 is a 4-character alphanumeric key. Once created and transactions are posted, this ID cannot be changed.
• The Company Code reference to the CoA (CAOH) and Fiscal Year Variant (K4) in OBY6 creates the binding chain: CoA → Fiscal Year Variant → Company Code. Without OBY6 assignment, assigning the Company Code to the Controlling Area in Step 1.9 will fail with error KT294.

Step 1.4 — Define & Assign Field Status Variant

Part A: Define the Field Status Variant

SAP Screen Flow

Screen 1 — Field Status Variant List

⚠️ Important: Do NOT click “New Entries.” Creating a blank Field Status Variant means it will have no field status groups inside it (meaning G001 won’t exist), which will cause FS00 to crash later. You must copy the standard SAP variant.

1. Select the row for standard variant 0001 (Field Status for 0001).
2. Click the Copy As… button (two overlapping squares icon) on the top toolbar.

Screen 2 — Copy As: Details

3. Overwrite the copied fields with our custom utility variant:

4. Press Enter.
5. SAP will display a prompt: “Copy all dependent entries?” → Click Copy all. (This is critical — it pulls in G001, G005, etc.)
6. SAP will confirm: “Number of dependent entries copied: XX”. Press Enter.
7. Click Save (Ctrl+S).
8. Confirm the transport request.

Part B: Assign Company Code to Field Status Variant

SAP Screen Flow

Screen 1 — Company Code → FSV Assignment Table

SAP displays a two-column table: Company Code | Field Status Variant.

1. Locate Company Code AEP1 in the list (or click New Entries if not visible).
2. Set the field:

3. Click Save (Ctrl+S).

Why This Step

The Field Status Variant controls which fields are required, optional, or hidden during financial document entry. Without this assignment, users will encounter screen errors when attempting to post any FI document (including the automated FI-CA postings from IS-U billing runs).

Step 1.5 — Define Posting Period Variant & Assign to Company Code

Part A: Define the Posting Period Variant

SAP Screen Flow

Screen 1 — Posting Period Variants Table

1. Click New Entries.

Screen 2 — New Entries: Details

2. Click Save (Ctrl+S).

Part B: Assign Variant to Company Code

SAP Screen Flow

Screen 1 — Company Code → Variant Assignment Table

1. Locate Company Code AEP1 in the list.
2. Set the field:

3. Click Save (Ctrl+S).

Part C: Open the Current Posting Periods

SAP Screen Flow

Screen 1 — Maintain Posting Period Variant: Overview

1. Enter Variant AEP1 in the header (or select it from the variant dropdown).
2. Click New Entries.

Screen 2 — New Entries: Posting Period Line

3. Click Save (Ctrl+S).

Why This Step

The Posting Period Variant controls which fiscal periods are open for posting. This is especially critical for IS-U because billing runs are automated batch processes — if the target posting period is closed, the entire billing run will fail with error F5 201. This variant allows independent period control per Company Code.

Step 1.6 — Define the Credit Control Area & Assign to Company Code

Part A: Define the Credit Control Area

SAP Screen Flow

Screen 1 — Credit Control Areas List

1. Click New Entries.

Screen 2 — New Entries: Details

2. Click Save (Ctrl+S).

Part B: Assign Company Code to Credit Control Area

SAP Screen Flow

Screen 1 — Company Code → Credit Control Area Assignment Table

1. Locate Company Code AEP1.
2. Set the field:

3. Click Save (Ctrl+S).

Why This Step

The Credit Control Area manages customer credit exposure. For a regulated utility, this is foundational for:

• Dunning processes (disconnect/reconnect workflows driven by credit exposure)
• Deposit management (Ohio regulators allow security deposits based on credit assessment)
• FI-CA credit integration (IS-U Contract Accounts inherit credit limits from this area)

Step 1.7 — Define Document Number Ranges for FI-GL

⚠️ Subledger Architecture Note: These number ranges are for the FI General Ledger only. Utility customer billing, payments, and collections happen entirely within the isolated FI-CA subledger — NOT in standard FI-AR (Accounts Receivable) or FI-AP (Accounts Payable). Therefore, we do not create FI-GL number ranges for customer invoices or vendor payments here. FI-CA has its own number ranges defined via FPN1 in Phase 2.

SAP Screen Flow

Screen 1 — Document Number Ranges: Company Code Selection

When you execute FBN1, SAP prompts for the Company Code.

1. Press Enter or click the green checkmark (✓).

Screen 2 — Number Range Maintenance: FI Documents

SAP displays the current number ranges (initially empty for a new Company Code).

2. Click the Change Intervals button (pencil icon 📝) on the toolbar.

Screen 3 — Maintain Intervals: Change

3. Click the Insert Interval button (➕ icon) to add a new row.

SAP presents an entry line with the following fields. Repeat for each number range:

Range 01 — General G/L Documents

4. Click Insert Interval (➕) again:

Range 19 — FI-CA Clearing Transfer to G/L

5. After both ranges are entered, click Save (💾) or press Ctrl+S.
6. SAP will display: “Number range intervals were saved.” Click the Back button (🔙) to return.

Summary Table

Why only 2 ranges? In a standard ERP, you would also create ranges for Customer Invoices (DR), Vendor Invoices (KR), etc. However, the utility manages all customer billing exclusively in the FI-CA subledger. FI-CA has its own isolated document number ranges (created via FPN1 in Phase 2, Step 2.2.2). The FI General Ledger only receives compressed summary postings from FI-CA via the Reconciliation Key transfer — and those use range 19 with document type ZC.

Why This Step

SAP requires pre-defined number ranges to assign sequential document numbers. Without these ranges, no financial document can be saved — the system throws error FO 117 (“Number range XX does not exist”). Range 19 is specifically reserved for the FI-CA to G/L transfer postings — the periodic compression and reconciliation of millions of subledger entries into summarized G/L entries.

Key Configuration Notes

• Year = 9999 means the range is valid for all years. If you set a specific year (e.g., 2026), the range would only be valid for fiscal year 2026, and you’d need to create new ranges annually — not recommended.
• NR Status is a display-only counter showing the last assigned number. It starts blank and auto-increments. You can manually set this field if migrating from a legacy system where you want SAP to continue numbering from a specific point.
• Ext (External) = unchecked means SAP auto-assigns numbers (internal numbering). If checked, the user must manually type a document number during posting — never used for automated IS-U billing processes.
• ⚠️ Number ranges must not overlap. If ranges 01 and 19 share any numbers, the system will reject the save with error NR 751.

Step 1.8 — Define Document Types (The Subledger Architecture)

⚠️ Architectural Note: A regulated utility handles millions of customers. We do not use standard SAP Accounts Receivable (FI-AR) or Accounts Payable (FI-AP) for utility billing. Customer billing, payments, and collections happen entirely within the isolated FI-CA subledger. Therefore:

• FI-GL document types (configured here via OBA7) handle only corporate G/L postings and the automated clearing documents received from FI-CA.
• FI-CA document types (configured in Phase 2 via table V_TFK003 / SM30) handle actual billing invoices, payments, and reversals.

Do NOT create standard FI-AR types like DR/DZ or FI-AP types like KR/KZ for utility billing. Those belong to a different subledger architecture (standard FI-AR) that is NOT used in IS-U.

Part A: General Ledger Document Types (FI-GL via OBA7)

SAP Screen Flow

Screen 1 — Document Types (Table View)

When you execute OBA7, SAP displays all existing document types. Many SAP-standard types already exist (SA, DR, KR, etc.).

Modify the Standard SA Document Type

1. Locate the row for document type SA and double-click it.

Screen 2 — Change View “Document Types”: Details

2. Click Save (Ctrl+S).

Create the Custom ZC Type for FI-CA Clearing

3. Click the Back button (🔙) to return to the table view.
4. Click New Entries.

Screen 3 — New Entries: Details

5. Click Save (Ctrl+S).

FI-GL Document Types Summary

⚠️ Important: Notice the absence of DR (Customer Invoice), DZ (Customer Payment), KR (Vendor Invoice), and KZ (Vendor Payment). These standard FI-AR/AP document types are intentionally excluded. Utility billing does not flow through FI-AR — it flows through FI-CA, which has its own document type namespace configured below.

Part B: Contract Accounting Document Types (FI-CA Subledger)

Note: This is a preview of the FI-CA document types. The full screen flow with number range creation is documented in Phase 2, Step 2.2.2 and Step 2.3. We introduce them here to complete the architectural picture.

These are the document types used by the SAP IS-U Billing Engine when a customer is billed, makes a payment, or has an invoice reversed:

The Z prefix follows SAP’s customer namespace convention for custom objects.

The Two-Tier Posting Architecture

┌─────────────────────────────────────────────────────────────────────┐
│  FI-CA SUBLEDGER (Isolated — Millions of individual transactions)  │
│                                                                     │
│  ZI (Invoice)  →  Customer owes $169.35                            │
│  ZP (Payment)  →  Customer pays $169.35                            │
│  ZD (Dunning)  →  Late fee $5.00 applied                           │
│                                                                     │
│  Individual line items per customer, per billing period              │
│  Managed via: Contract Account → Business Partner                   │
└────────────────────────┬────────────────────────────────────────────┘
                         │
                         │  Periodic Transfer (T-Code: FPG1)
                         │  Compressed via Reconciliation Key
                         │
                         ▼
┌─────────────────────────────────────────────────────────────────────┐
│  FI GENERAL LEDGER (Corporate — Summarized journal entries)         │
│                                                                     │
│  ZC (Clearing)  →  Debit: 1200000000 (AR)      $1,250,000.00      │
│                    Credit: 4100000000 (Revenue)  $1,250,000.00      │
│                                                                     │
│  One aggregated entry for thousands of individual FI-CA postings    │
│  Posted to Number Range 19                                          │
└─────────────────────────────────────────────────────────────────────┘

Why This Architecture

A standard General Ledger would collapse under the volume of utility transactions. With 500,000+ customers billed monthly, FI-CA processes millions of individual line items. The two-tier architecture:

1. FI-CA handles high-volume, customer-level transactions with optimized indexing and mass-processing capabilities
2. FI-GL receives only compressed, summarized postings — keeping the General Ledger clean for financial reporting and audit
3. The Reconciliation Key (Phase 2, Step 2.6) controls the compression and transfer frequency

Step 1.9 — Define the Controlling Area

SAP Screen Flow

Screen 1 — Controlling Area: Initial Screen

When you execute OKKP, SAP displays a tree structure on the left side with options:

• Maintain Controlling Area
• Assign Company Code

Part A: Create the Controlling Area

1. Select Maintain Controlling Area in the tree.
2. Click New Entries.

Screen 2 — New Entries: Controlling Area Details

3. Click Save (Ctrl+S).
4. ⚠️ SAP Interacts: A warning dialog will appear stating: “Standard hierarchy AEP1 does not exist. Should system create standard hierarchy AEP1?”
5. Click Yes. (This automatically generates the top-level node for the hierarchy we’ll use in Step 1.10).

Part B: Assign Company Code to Controlling Area

6. In the left-hand tree, select Assign Company Code.
7. Enter Controlling Area AEP1.

Screen 3 — Assignment Table

8. Click Save (Ctrl+S).

Part C: Activate Components/Control Indicators

9. Go back to the main tree → select Activate Components/Control Indicators.
10. The right-hand pane will show “Existing Fiscal Year Intervals” (currently empty: Entry 0 of 0).
11. Click the New Entries button on the top toolbar.

Screen 4 — Component Activation Details

12. The system prompts for a Fiscal Year and component flags. Fill them in:

13. Click Save (Ctrl+S).

Why This Step

The Controlling Area is the organizational unit for management accounting. In IS-U, it serves as the link between utility billing revenue and internal cost allocation. When a billing document posts revenue to an FI G/L account, the Controlling Area simultaneously records the associated profitability to a Profit Center (e.g., “Residential Columbus,” “Commercial Columbus,” “Industrial Columbus”).

Key Configuration Notes

• Set the Controlling Area to Company Code assignment as 1:1 (one controlling area to one company code). This is the standard model for a single regulated utility.
• Ensure the Chart of Accounts matches (CAOH) — the CO module must post to the same G/L accounts as FI.

Step 1.10 — Create Essential Cost Centers

SAP Screen Flow

Screen 1 — Create Cost Center: Initial Screen

When you execute KS01, SAP prompts for initial parameters.

1. Press Enter.

Screen 2 — Create Cost Center: Basic Data

2. Click Save (Ctrl+S).

Repeat the entire process (KS01) for each additional cost center:

Why This Step

Cost Centers are required for any expense allocation in the system. IS-U processes like meter deployment, billing run execution, and print/mail operations will need cost objects. Creating these now establishes the CO structure before IS-U generates any cost-relevant transactions.

Step 1.11 — Verify Units of Measure (Critical for EDM)

SAP Screen Flow

Screen 1 — Units of Measurement: Initial Screen

When you execute CUNI, SAP presents a selection screen.

1. In the Unit of Measurement field, enter KWH.
2. Press Enter or click Display (👓).

Screen 2 — Unit of Measurement Details

Verify the following fields are correctly configured:

3. If any field is incorrect, click Change (pencil icon), correct it, and Save.

Repeat verification for all required UoMs:

⚠️ This must be verified before Phase 4. If KWH does not exist with the correct ISO mapping, EDM profile allocation will fail silently and interval data will not flow into billing.

Why This Step (⚠️ Critical EDM Prerequisite)

Units of Measurement are global SAP objects (client-level), not company-code-specific. They are the atomic foundation for:

• Device Management: Register units on meters (KWH, KW)
• Energy Data Management: All interval data profiles store values in these units
• Billing: Rate calculations convert metered consumption (KWH) to monetary amounts (USD)

Phase 1 — Completion Checklist

🔗 All Phase 1 prerequisites are now in place. Proceed to Phase 2: IS-U Basic Settings & FI-CA Integration.