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

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 1. Runs on a schedule every Monday at 8:00 AM. 2. Reads procurement transaction rows from Google Sheets. 3. Aggregates the data to calculate spend by category and supplier, supplier counts per category, item-level price statistics, and preferred vs non-preferred spend. 4. Detects savings opportunities using rules for supplier fragmentation, price variance, maverick spend, and contract leakage. 5. Sends the detected opportunities to OpenAI (GPT-4o Mini) to produce structured analyses with savings estimates, effort levels, and recommended actions. 6. 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. 7. Builds an HTML email with the top 5 opportunities by priority score and sends the weekly savings report via Gmail. Setup 1. 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. 2. Add Google Sheets OAuth credentials in n8n and update the spreadsheet ID and sheet tabs used for reading transactions and appending opportunities. 3. Add an OpenAI credential (Chat Completions) and ensure the workflow can use the GPT-4o Mini model. 4. 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). 5. Add Gmail OAuth credentials and set the recipient(s) in the Gmail “Send Weekly Savings Report” step. 6. 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