Interview Questions › Root Cause Analysis

Customer support tickets for “wrong item delivered” increased

Customer support tickets categorized as "Wrong Item Delivered" surged by 35% over the past two weeks. Investigate the operational or technical failure.

Context

Returns and refund requests are clustering around specific product categories in 3 fulfillment centers.

Clarifying questions to ask first

• Is this across all warehouses or specific facilities?
• Are specific SKUs or categories overrepresented?

How to approach it

1. Clarify timeline and geographic concentration of affected orders
2. Segment by Fulfillment Center (FC), Product Category, Seller Type (1P vs 3P Marketplace), and Barcode/SKU mapping
3. Investigate warehouse picking software updates, barcode scanner glitches, and multi-pack bundling errors
4. Synthesize root cause and preventative SOP safeguards

Framework: Geographic & Fulfillment Center Segmentation -> SKU / Barcode Mapping -> Warehouse Picking Workflow -> Seller Catalog Errors

Sample answer

• Barcode collision on newly imported vendor SKUs
• Warehouse sorting conveyor optical scanner calibration error
• Third-party seller mislabeling ASIN barcodes during inbound FBA

1. Isolate 80% of wrong item tickets to 2 fulfillment centers in Midwest
2. Trace back to a barcode scanner firmware patch that truncated leading zeros on UPC barcodes

Firmware bug in FC optical scanners caused UPC truncation and misdirected picking bins; patched firmware and audited bin inventory.

What interviewers look for

• Wrong Item Rate (% of Orders)
• Return Authorization Rate
• Warehouse Picking Accuracy
• Support Ticket Volume by Category