Forfis Blog

Tag: Invoice Processing

  • 4-Week AI Pilot: Invoice Processing and RAG Assistant for a B2B SaaS in Austria

    The Problem: Manual Back-Office Work and Slow First-Response in a 201-500 Employee B2B SaaS

    Your operations and supply chain team in Vienna processes 1,200 invoices monthly, each taking 14 minutes of manual data entry, and your support desk answers 300 tickets a week with a median first-response time of 4.2 hours. The back-office work is repetitive, error-prone, and consuming 3.5 FTEs that could be redeployed. The EU AI Act, in force since August 2024, requires you to document your AI risk assessment before deploying any automated system that touches financial data. You need a fixed-scope pilot that delivers a measured before/after baseline in 4 weeks, not a 6-month transformation program. The pilot must work within your existing stack — Notion for documentation, your CRM for customer records, your ERP for invoice data — and must keep regulated data on Austrian infrastructure.

    Prerequisites Before Step 1

    • Process audit completed: You have mapped the invoice processing workflow from receipt to payment, timed each step, and counted error types. The audit output is a one-page document with baseline metrics: average cycle time (hours), error rate (%), and FTE hours consumed.
    • n8n instance deployed: A self-hosted n8n instance runs on your Austrian cloud or on-premises server. You have API credentials for your CRM, ERP, and helpdesk. The n8n version is 1.40 or later for stable webhook and AI node support.
    • RAG source material ready: Notion or Confluence contains at least 50 pages of operational documentation — vendor onboarding, invoice coding rules, escalation paths, SLA definitions. The content is current (updated within the last 30 days).
    • Human-in-the-loop approvers identified: You have named 2–3 people who will approve AI-drafted invoice entries and ticket responses. They understand the approval criteria and have access to the n8n approval UI.
    • EU AI Act risk assessment drafted: A one-page document classifying your RAG assistant as a limited-risk system, noting the transparency obligations, and confirming no special-category data is processed without consent.
    • Fixed-scope statement of work signed: The pilot scope, success metrics, and 4-week timeline are locked. No scope changes without a change order.

    Step 1: Run the Process Audit and Lock the Baseline

    Run a 2-hour process audit with your operations lead. Map every step from invoice receipt (email, portal, or EDI) to payment posting in the ERP. Time each step with a stopwatch or screen-recording tool. Count error types over the last 30 days: wrong vendor code, duplicate entry, missing tax ID, incorrect tax rate. Record the baseline: average cycle time in hours, error rate as a percentage, and total FTE hours consumed. Output: a one-page audit document with a workflow diagram and a table of error types with frequencies. This document is your before/after measurement anchor. Do not proceed to Step 2 until the baseline is signed off by the operations lead.

    Step 2: Build the n8n Invoice Extraction Workflow

    Build the n8n workflow for invoice extraction. Create a webhook node that receives the invoice PDF via email or ERP API. Add an AI node using OpenAI’s GPT-4o or Anthropic’s Claude 3.5 Sonnet for extraction — these models handle multi-column invoice layouts with 94–97% field accuracy on standard B2B invoices. Configure the extraction schema: vendor name, vendor tax ID, invoice number, line items, tax rate, total amount, due date. Add a validation node that checks for missing fields and flags anomalies (e.g., tax ID format mismatch, total exceeds PO amount by more than 5%). Route flagged invoices to a human approval node in n8n; route clean invoices to the ERP write-back node. Test with 50 historical invoices before going live.

    Step 3: Build the RAG Knowledge Assistant Over Notion or Confluence

    Set up the RAG index over your Notion or Confluence documentation. In n8n, create a workflow that pulls pages on an hourly schedule using the Notion API node or Confluence Cloud API. Chunk the content at 512 tokens with 64-token overlap. Embed using BGE-M3 or Cohere embed-v3 — both handle English and German, which matters for your Austrian team. Store embeddings in pgvector on your PostgreSQL instance. Build the RAG query workflow: receive a ticket or question, retrieve the top-5 chunks, pass them as context to the LLM, and return a grounded answer with source citations (page title and URL). Test with 20 real questions from your support team. If retrieval hit-rate is below 85%, re-chunk or re-embed. The RAG assistant must never answer without a source citation.

    Step 4: Integrate with CRM, ERP, and Helpdesk

    Integrate the n8n workflows with your existing systems. For the invoice workflow: connect the ERP write-back node to your ERP’s API (SAP, NetSuite, or similar) using the vendor’s REST or SOAP endpoint. For the RAG assistant: connect the helpdesk (Zendesk, Freshdesk, or Jira Service Management) via webhook so that incoming tickets trigger the RAG query workflow. The RAG workflow drafts a response, attaches the retrieved context, and routes it to the human approver. The approver edits or approves in the n8n UI, and the approved response sends via the helpdesk API. All integrations use your existing API credentials — no new accounts, no new systems. Test each integration with 10 real transactions in a staging environment before moving to production.

    Step 5: Run the 4-Week Pilot with Human-in-the-Loop Approval

    Run the pilot in shadow mode for 2 weeks. The n8n workflows process real invoices and tickets, but the human approver reviews every output before it reaches the ERP or the customer. Track three metrics daily: cycle time (from invoice receipt to ERP posting, or from ticket creation to first response), error rate (AI-drafted entries rejected or edited by the approver), and human-override rate (percentage of AI outputs that required manual correction). At the end of 2 weeks, compare against the Step 1 baseline. The pilot report must show: cycle time reduction in hours, error rate change in percentage points, and FTE hours saved. If cycle time drops by 40% or more and error rate stays below 5%, the pilot is a success. If not, diagnose the failure mode before proceeding to rollout.

  • Swiss E-commerce Cuts Invoice Cycle Time 92% in a Two-Week ISO 27001-Safe Pilot

    Background: A Swiss Retail Group Under Audit Pressure

    This case study is a composite drawn from patterns observed across multiple engagements. No named customer is represented. The details are plausible and reflect the range of outcomes seen in the field, but they do not describe a single real company.

    The client is a Swiss e-commerce and retail group with roughly 2,400 employees, operating in German, French, and Italian markets. The finance and accounting team handles 18,000 to 22,000 supplier invoices per month across three ERP instances. The stack is a mix of SAP S/4HANA for the core ledger, a legacy document management system for invoice images, and Confluence for internal runbooks and audit documentation. The company holds ISO 27001 certification and is in the middle of a renewal audit. The finance director’s mandate was clear: reduce the average cycle time from invoice receipt to ERP posting without introducing a compliance gap.

    Challenge: 20,000 Invoices a Month and a 90-Day Audit Clock

    The finance team was processing invoices manually: a clerk downloaded the PDF, typed the vendor name, amount, tax code, and cost center into the ERP, and flagged discrepancies for review. The average cycle time was 4 to 6 hours per invoice, with a 3 to 5 percent error rate on a sample of 500 invoices. The error rate was not just a cost issue; it was a compliance issue. ISO 27001 requires documented controls over financial data, and a 4 percent error rate on 20,000 invoices per month meant roughly 800 mis-posted entries that had to be caught in a secondary review. The secondary review was itself a manual process, adding another 2 to 3 hours per flagged invoice. The finance director had a deadline: the ISO 27001 renewal audit was 90 days out, and the auditor had already flagged the manual process as a control weakness.

    Approach: A Two-Week Pilot on the Top Five Vendors

    The engagement started with a three-day process audit. The team mapped the invoice lifecycle from receipt to posting, identified the 12 vendor categories that accounted for 78 percent of volume, and pulled a historical sample of 1,200 invoices for calibration. The pilot scope was fixed: one ERP instance, one vendor category (the top 5 suppliers by volume), and a two-week window. The architecture used the OpenAI API for extraction, with a human-in-the-loop approval queue. The model extracted vendor name, invoice number, amount, tax code, and cost center. A reviewer saw the proposed entry alongside the original PDF and could approve, correct, or reject. The approval log was written to Confluence and to the ERP audit trail. The pipeline connected to the ERP via its REST API and to the document store via SFTP. No new infrastructure was required. The client’s existing IT team handled the API credentials and network access.

    Outcome: 92 Percent Cycle-Time Reduction in 12 Days

    The pilot ran for 12 business days. The model processed 1,840 invoices from the top five vendors. The average cycle time dropped from 4.2 hours to 22 minutes, a 92 percent reduction. The error rate on the pilot sample was 0.8 percent, down from the 3.4 percent baseline. Of the 1,840 invoices, 1,612 were approved with zero edits. The remaining 228 required human correction, mostly on tax codes for cross-border invoices. The approval queue averaged 14 minutes per invoice for the corrected entries. The ISO 27001 audit trail showed 100 percent of inferences logged with timestamp, user ID, and confidence score. The finance director presented the pilot results to the audit committee. The auditor accepted the AI-assisted workflow as a control improvement, conditional on the managed operations SLA being in place before the renewal audit.

    Lessons for Teams Running Similar Pilots

    • The historical sample matters more than the model. The 1,200-invoice calibration sample was the single biggest factor in the 0.8 percent error rate. A team that skips this step and goes live with a generic prompt will see error rates of 8 to 12 percent and lose the human trust needed for the approval workflow.
    • Fix the scope before you start. The two-week window only worked because the pilot was limited to one ERP instance and five vendors. A team that tries to cover all 12 vendor categories in two weeks will spend the time on integration edge cases and miss the baseline measurement.
    • The approval queue is the product, not the model. The model’s extraction quality was good, but the reviewer interface was what made the workflow usable. A team that ships a model without a clean approval UI will see reviewers bypass the system and go back to manual entry.
    • ISO 27001 is a design constraint, not a post-hoc checkbox. The audit trail, the data processing agreement, and the access controls were built into the architecture from day one. Retrofitting them after go-live is 3 to 4 times more expensive and often fails the audit.
    • Managed operations is where the value compounds. The pilot proved the concept. The managed operations SLA, with monthly reports on confidence distribution and error rate, is what keeps the error rate at 0.8 percent instead of drifting to 3 percent as vendor formats change.