If you have worked as a Planning or Billing Engineer on an EPC project, you have probably experienced this: your schedule lives in Primavera P6, your financials sit in SAP, and your Running Account (RA) bill is being built — again — in a separate Excel sheet. Every month. Despite the enterprise software your organisation spent millions to implement.
This is not a failure of discipline. It is a structural limitation of tools that were not designed with EPC billing workflows at their core. This article documents those gaps, drawing on published industry sources and community documentation, and outlines what a purpose-built EPC solution should address.
Disclaimer: SAP, Oracle Primavera P6, and Microsoft Project are well-established platforms used across many industries. The observations below are specific to EPC RA billing workflows and are drawn from publicly available, third-party industry sources and vendor documentation. They do not reflect on the overall quality of these products. Individual results vary significantly by implementation and configuration. ACGIL's Mx-ERP is offered as a complementary or alternative solution for EPC-specific use cases.
1. SAP Project Systems (PS) — Powerful, but Demanding to Configure for EPC Billing
SAP PS is an enterprise-grade platform and, for large organisations managing multi-project portfolios, its financial rigour is a genuine asset. The challenges surface when EPC site realities meet SAP's structured billing approach.
Commonly Documented Gaps in EPC Billing Environments
- Resource-Related Billing complexity: SAP's standard mechanism for project-based billing is Resource-Related Billing (RRB) via DIP profiles. Community documentation confirms that DIP profile configuration can involve significant complexity — determining sales items through dummy materials and requiring careful alignment between WBS, SD orders, and revenue recognition. [2]
- RA process and WIP settlement: EPC teams using SAP PS report that projects cannot be closed if WIP values remain unsettled, and that RA processes must be carefully sequenced at period-end to avoid incorrect financial postings. [3]
- Revenue linking limited to WBS level: SAP's own Q&A documentation confirms that revenues cannot be directly linked to individual network activities — only to WBS elements with the Billing operative indicator enabled. For EPC teams that bill at activity level, this requires workarounds. [4]
- Cumulative deduction and retention handling: A standard EPC RA bill bundles material advance recovery, retention (typically 5–10%), GST adjustments, and penalties into one document. Handling this combination in SAP standard functionality typically involves configuration effort and, in some cases, custom development.
- Progress-to-billing lag: Physical measurement books and BOQ reconciliation are frequently managed outside SAP and manually posted into the system for financial reporting — creating a gap between certified work and billed amounts.
Field observation
Many EPC organisations run SAP alongside a separate Excel-based measurement system, with a reconciliation step at month-end before financial posting. The integration work is often manual and a recurring source of billing cycle delays.
2. Oracle Primavera P6 — The Industry Standard for Scheduling, with Real Gaps in Billing
Primavera P6 is the industry standard for large-scale EPC scheduling — a reputation it has earned. Oracle's own documentation positions P6 as a scheduling and resource management tool, requiring integration with a financial ERP for cost and billing workflows. [9]
Documented Limitations in Financial and Billing Control
- No invoicing or billing capability: According to Planning Engineer FZE, an independent industry knowledge platform, Primavera P6 does not handle invoicing, cash flow management, or payments — requiring integration with an ERP such as SAP or Oracle Financials for these functions. [1]
- No real-time cost integration: P6 does not automatically sync with procurement or finance systems, making real-time cost tracking unavailable within the tool itself. Actual cost data must be entered manually. [5]
- Manual cost updates: Actual cost data must be entered manually and recorded in Store Period Performance to ensure accurate period-level estimation — a process that can introduce delays and errors in financial reporting. [1]
- Limited cash flow forecasting: While P6 can generate cash flow reports, it does not provide dynamic forecasting that adjusts automatically to real-time financial changes. [5]
- Scale and cost threshold: Independent comparisons note that P6 is most suited to large-scale enterprise projects — for smaller EPC contracts, the licensing and training investment may not be commercially justified. [6]
Important note
Primavera P6 remains the scheduling tool of choice for large EPC projects. Oracle itself recommends integrating P6 with financial ERP systems (such as Oracle Unifier or SAP) to address the billing and cost management gaps noted above. The limitations described here relate specifically to EPC billing workflows — not to P6's core scheduling capability.
3. Microsoft Project — Effective for Smaller Schedules, Not Designed for EPC Billing
MS Project is widely used for scheduling small to mid-size projects and internal programmes. For EPC RA billing, it was not designed for this purpose. Independent analysis confirms that MS Project suits smaller, simpler projects, with Primavera P6 preferred for large-scale EPC complexity. [6]
Documented Gaps in EPC Billing Environments
- No invoicing or billing module: MS Project (the standalone scheduling application) does not generate RA bills, Payment Certificates, or tax invoices. Billing engineers use it only for progress status and maintain billing records in SAP or Excel separately. Note: Microsoft's broader Dynamics 365 ecosystem does support EPC billing, but this requires a separate product stack beyond MS Project. [8]
- EPC-specific gaps require ISV solutions: Community analysis of the Microsoft ecosystem for EPC confirms that processes like RA bills, BOQ-linked progress measurement, and subcontractor billing require dedicated ISV (third-party) solutions or customisation on top of standard Microsoft tools. [8]
- ERP integration required for financial control: Published construction ERP analysis highlights that financial accuracy in construction requires connecting scheduling tools with ERP — and that without this, finance teams reconcile spreadsheets instead of managing cash, contributing to the high rate of ERP implementation failures in construction. [7]
- Manual progress updates: Site-level progress requires manual input into MS Project, creating lags between physical completion and reported status — a meaningful problem when billing is tied to certified progress.
At a Glance: Common EPC Billing Gaps by Tool
Based on published industry sources and vendor documentation. Results vary by implementation version and configuration. [1] [2] [5] [6]
| Challenge Area | SAP PS | Primavera P6 | MS Project |
|---|---|---|---|
| RA / Progress Billing | Requires DIP profile & custom config | No billing module — ERP integration needed | No billing module |
| Field Integration | Manual / batch posting | Manual cost updates required | Manual data entry |
| Subcontractor Mgmt | Complex, activity-level billing difficult | Limited — scheduling focus only | Not natively supported |
| Variation Handling | WBS changes require admin involvement | Rigid WBS structure | External tools needed |
| Real-Time Cost Sync | Config-heavy | No real-time cost integration | Requires ERP bridge |
| Best Suited For | Large enterprise portfolios | Large-scale scheduling | Small-mid projects |
4. What an EPC-Purpose-Built Solution Should Address
Research by Advaiya (citing Rabbet and Billd, 2025) found that in 2024, 82% of contractors reported payment delays exceeding 30 days — and that when ERP systems cannot track retainage or surface WIP variances in real time, finance teams end up reconciling spreadsheets instead of managing cash flow. [7]
A purpose-built EPC ERP solution — whether standalone or integrated with existing platforms — should natively address:
- Flexible progress-to-billing workflows that accommodate cumulative deductions, retention, GST, and variation tracking in a single RA bill document — without requiring ERP administrator involvement for scope changes
- Real-time sync between physical progress (measurement books, BOQ, site certifications) and financial billing — eliminating the month-end Excel reconciliation step
- Subcontractor billing management with deduction, withholding tax, and retention handling built in
- Integration capability with existing SAP or financial ERP for organisations that need to retain their financial backbone
- Commercial viability for mid-size EPC projects where full SAP PS or Primavera implementation is not justified by contract value
About ACGIL Mx-ERP for EPC
ACGIL's Mx-ERP is a web-based ERP platform designed for Engineering, Procurement, and Construction companies. It integrates project scheduling, RA billing, quantity auditing, subcontractor management, procurement management, and finance into a single real-time platform. It can function as a standalone EPC management system or be integrated with existing financial tools. For teams currently managing RA bills in Excel alongside SAP or Primavera, Mx-ERP is designed to close that gap. Key Benefits of Using Mx-ERP:
- Integrated Cost Control
- Accurate Procurement & Materials Management
- Enhanced Earned Value Management (EVM)
- Improved Resource Management
- Elimination of Data Silos
- Improved Cash Flow Forecasting
Closing Thoughts
The EPC industry is not short of software. It is short of software that actually fits the billing engineer's daily workflow without requiring manual workarounds every month. If your team is spending significant time reconciling systems at month-end before issuing an RA bill, that is the gap worth solving — regardless of which tool you choose to address it.
If you have experienced similar challenges — or found ways to make SAP, Primavera, or MS Project work well for RA billing — we would welcome the conversation in the comments.
Interested in seeing how Mx-ERP handles EPC billing workflows?
Request a demo at www.acgil.com or reach out directly via LinkedIn.
Sources & References
- [1] Planning Engineer FZE — "What are the Limits of Performing Cost Control using Primavera P6" (April 2025) https://planningengineer.net/what-are-the-limits-of-performing-cost-control-using-primavera-p6/
- [2] SAP Community — Resource Related Billing: complexity of DIP profile setup https://answers.sap.com/questions/12927316/resource-related-billing-benefits-with-ps-and-inte.html
- [3] SAP Community Discussion — RA value and WBS settlement, project closing with WIP https://discussion217.rssing.com/chan-15285350/all_p111.html
- [4] SAP Press / SAP Help — Billing with SAP Project System in SAP S/4HANA: Resource-Related Billing and DIP profiles https://blog.sap-press.com/billing-with-sap-project-system-in-sap-s4hana
- [5] Planning Engineer FZE — Primavera P6 cost control limits: no real-time cost integration, manual actual cost entry https://planningengineer.net/what-are-the-limits-of-performing-cost-control-using-primavera-p6/
- [6] Famcod — "Microsoft Project vs Primavera: Differences (2026 Guide)" — scale and scope comparison https://famcod.com/microsoft-project-vs-primavera-differences-2026-guide/
- [7] Advaiya / Rabbet / Billd — "Why 70% of construction ERP implementations fail" (March 2026): payment delays, retainage, WIP reconciliation challenges https://advaiya.com/construction-erp-implementations-fail-dynamics-365-business-central/
- [8] Windows Forum — Community discussion: EPC-specific gaps in Microsoft ecosystem for RA bills, subcontractor billing, progress measurement (April 2026) https://windowsforum.com/threads/how-well-does-dynamics-365-or-business-central-support-end-to-end-epc-project-management-especially-for-integrating-engineering-procurement.408692/
- [9] Oracle Primavera P6 EPPM Official Datasheet — product scope and integration requirements https://www.oracle.com/construction-engineering/primavera-p6/datasheet/
ACG Infotech Limited (ACGIL) | CMMI Level 3 | ISO 9001 | ISO 27001 | ISO 20000
