Summary Modern Version

FUNCTIONAL REQUIREMENTS DOCUMENT

FRD-AR500-MODERN – Next-Generation Batch A/R Aged Trial Balance API / Service (2026+)

1. Business Objective & Summary

Replace the 35-year-old AR500 OCL/RPG suite with a modern, callable, fully reconciled A/R Aged Trial Balance service that can be invoked from any platform (RPG-ILE, Python, Node.js, Java, Power Automate, etc.) via a simple program call, REST API, or message queue.

The new service will: - Produce the exact same trusted, penny-perfect numbers as the current suite
- Permanently re-age the live A/R files exactly as AR390 does today
- Deliver the report in PDF + optional Excel/CSV
- Eliminate obsolete options (NOD flag, Salesman sequence) while keeping the core accounting integrity intact

This is not a cosmetic rewrite – it is a strategic modernisation that preserves the single most important reconciliation report in the company while making it callable from anywhere.

2. Modern Call Interface (Example – ILE RPG or REST)

CALL PGM(AR500NG) PARM(
     asOfDate       /* '2025-11-30'       YYYY-MM-DD     */
     companyList    /* '01,05,ALL'               */
     custClass      /* '' or 'GOV,HIGH'          */
     sequence       /* 'C' or 'N'                */
     includeCreditLimitFlag /* 'Y' or 'N'         */
     outputFormat   /* 'PDF', 'EXCEL', 'BOTH'    */
     returnJobId    /* 10-digit job number out   */
)

Or via REST POST /api/ar-aged-trial-balance

3. Input Parameters (Modernised & Slimmed Down)

Position / Name	Type	Mandatory?	Valid Values / Meaning	Notes / Changes from Legacy
asOfDate	Date / String	Yes	YYYY-MM-DD or YYYYMMDD	Mandatory ageing date
companyList	String	Yes	Comma-separated list or 'ALL'	Replaces 111–119
custClass	String	No	Blank = all, or comma-separated list (e.g. 'GOV,HIGH')	Replaces 130–150
sequence	Char(1)	Yes	'C' = By Customer Number 'N' = By Customer Name	'S' (Salesman) permanently removed
includeCreditLimitFlag	Char(1)	No	'Y' = show & highlight over-limit customers 'N' = hide	Replaces position 153
outputFormat	String	No	'PDF', 'EXCEL', 'BOTH' (default = PDF)	New – modern formats
requestId / correlationId	String	No	For async calls / logging

Explicitly Removed Legacy Options
- NOD (position 161) → permanently removed – zero-balance customers are now always suppressed (this is the 2025 business standard)
- Salesman sequence ('S'), salesman range, salesman copies (positions 152, 154–162) → permanently removed – no longer supported

4. Core Process Steps (Same Trusted Logic – Modern Implementation)

1. Re-age all open items
2. Basis: Days overdue from due date (standard since 2022)**
3. Bucket calculation:
   DaysOverdue = AsOfDate – DueDate
   Bucket 1 (Current): DaysOverdue ≤ ACLMT1
   Bucket 2: ACLMT1 + 1 ≤ DaysOverdue ≤ ACLMT2
   …
   Bucket 5 (Over): DaysOverdue > ACLMT4
4. Physically update ADAGE in every ARDETL record

5. Update packed AGE(1)–AGE(5) and high-balance fields in every ARCUST record

6. Apply company & customer-class filters

7. Extract only customers matching companyList and custClass (if supplied)

8. Suppress zero-balance customers

9. Hard-coded rule: any customer with recalculated balance = 0 is excluded (former NOD=Y is now default)

10. Sort

11. 'C' → by Customer Number

12. 'N' → by Last Name Abbreviation (ARLSTN)

13. Reconcile & generate output

14. Recalculate every customer balance from detail
15. Compare to ARCUST.ARTOTD → raise alert if different
16. If includeCreditLimitFlag = 'Y' → compare to ARCLMT → highlight over-limit with “**”
17. Produce PDF (164-column layout identical to AR750) + optional Excel/CSV

5. Key Business Rules (Clarified & Hardened)

Rule	Detail
Ageing basis	Always by due date – days overdue = AsOfDate – DueDate
Bucket boundaries	Defined once per company in ARCONT (ACLMT1–ACLMT4) – 5 buckets total
Zero-balance suppression	Always on – customers with $0 balance are never shown (former NOD=Y is now mandatory)
Reconciliation	100% mandatory – detail total must equal ARCUST.ARTOTD or alert is raised
Credit limit highlighting	Optional – when requested, “**” shown if recalculated balance > ARCLMT
Grouping hierarchy	Child customers inherit parent’s salesman and name for sorting (preserved)
Salesman reporting	Removed – no longer available (use separate commission reports instead)
Output formats	PDF (official audit trail) + optional Excel/CSV for analysis

6. Outputs

• PDF spooled file or stream (exact replica of current AR750 layout)
• Optional Excel/CSV file (modern replacement for old ARATBS)
• Permanent update of ageing codes and high-balance history in live files
• Return code + job/log ID for monitoring

This modernised service preserves 30+ years of accounting trust** while eliminating obsolete options and enabling seamless integration into today’s enterprise systems.