Hook:  Hard-coded paths are silent project killers. Move a file, share a workbook, or publish a PBIX—and boom: refresh fails. Goal:  In ~10 minutes you’ll set up robust, parameter-driven paths for Excel (Power Query) and Power BI (Desktop & Service), plus a tiny, reusable M pattern you can paste into any project. 1) Why hard-coded paths fail When you embed "C:\Users\Alice\Project\data.csv" in a query, anyone whose files live elsewhere (e.g., D:\Work\Data\) will get errors. I