Analyze procurement savings opportunities with Google Sheets, GPT-4o Mini, and Gmail

Description

Quick overview
This workflow runs every Monday, analyzes procurement transactions from Google Sheets to detect savings opportunities, uses OpenAI (GPT-4o Mini) to generate recommendations and savings estimates, prioritizes the results, saves them back to Google Sheets, and emails a weekly top-5 savings report via Gmail.

How it works
Runs on a schedule every Monday at 8:00 AM.
Reads procurement transaction rows from Google Sheets.
Aggregates the data to calculate spend by category and supplier, supplier counts per category, item-level price statistics, and preferred vs non-preferred spend.
Detects savings opportunities using rules for supplier fragmentation, price variance, maverick spend, and contract leakage.
Sends the detected opportunities to OpenAI (GPT-4o Mini) to produce structured analyses with savings estimates, effort levels, and recommended actions.
Scores and ranks opportunities by impact versus effort, classifies them (Strategic Initiative/Quick Win/Low Priority), and appends the results to a second Google Sheets tab.
Builds an HTML email with the top 5 opportunities by priority score and sends the weekly savings report via Gmail.

Setup
Create a Google Sheets spreadsheet with a transactions tab that includes columns for Category, Supplier, Item Description, Quantity, Unit Price, Total Spend, Contract Price, and Preferred Supplier.
Add Google Sheets OAuth credentials in n8n and update the spreadsheet ID and sheet tabs used for reading transactions and appending opportunities.
Add an OpenAI credential (Chat Completions) and ensure the workflow can use the GPT-4o Mini model.
Create an output tab in Google Sheets with columns matching the fields the workflow appends (Analysis Date, Opportunity Type, Category, Description, Savings Amount, Effort Score, Priority Score, Classification, Status).
Add Gmail OAuth credentials and set the recipient(s) in the Gmail “Send Weekly Savings Report” step.
Update the failure alert email (and the execution URL placeholder) so error notifications go to the right stakeholders in your n8n environment.

Additional info
How To Customize Nodes

Read Procurement Data

Customize:

Data source sheet
Additional procurement fields

Opportunity Detection

Adjust thresholds such as:

Supplier count limits
Price variance percentages
Contract leakage thresholds
Maverick spend criteria

AI Opportunity Analysis

Customize:

Prompt instructions
Savings assumptions
Recommendation style
OpenAI model

Priority Scoring

Modify:

Impact scoring logic
Effort scoring weights
Classification thresholds

Email Report

Customize:

Top opportunities count
Email design
Additional metrics
Stakeholder groups

Add-Ons

Possible enhancements include:

Slack notifications
Microsoft Teams alerts
Power BI dashboards
Looker Studio reporting
Vendor performance scorecards
Approval workflows
Procurement KPI tracking
Historical trend analysis
Supplier risk monitoring
Automated sourcing recommendations

Use Case Examples

1. Supplier Consolidation

Identify categories with excessive supplier fragmentation and estimate consolidation savings.

2. Contract Compliance Monitoring

Detect purchases made above negotiated contract rates.

3. Maverick Spend Reduction

Monitor spending outside approved supplier programs.

4. Procurement Cost Optimization

Identify categories with the highest savings potential.

5. Executive Spend Reporting

Provide leadership with prioritized savings opportunities each week.

Additional use cases can be created by extending the business rules and AI analysis layer.

Troubleshooting Guide

| Issue | Possible Cause | Solution |
|---------|---------|---------|
| No data returned from Google Sheets | Incorrect Sheet ID or permissions | Verify document access and credentials |
| AI node fails | Invalid OpenAI credentials | Reconnect OpenAI account |
| No opportunities detected | Dataset does not meet thresholds | Review detection rules and sample data |
| Email not sent | Gmail authentication issue | Reauthorize Gmail connection |
| Opportunities not saved | Destination sheet mismatch | Verify sheet mapping configuration |
| Incorrect savings estimates | AI output variation | Refine AI prompt instructions |
| Workflow stops unexpectedly | Node execution error | Review execution logs and error output |

Need Help?

If you need assistance customizing this workflow or building additional procurement automation solutions, WeblineIndia can help with:

n8n workflow customization
Procurement automation
AI-powered business process automation
Dashboard development
ERP and procurement system integrations
Reporting and analytics solutions
Custom workflow enhancements

Whether you need additional integrations, custom business rules or enterprise-grade procurement automation, professional support by hiring n8n workflow developers can help accelerate implementation and maximize business value.