Power BI Relationships & Dashboard

My current Power BI report pulls from several Excel tables and the model has grown messy. Multiple relationships are clashing, producing duplicates and inaccurate aggregations. I need those relationships untangled so each table connects through a single, reliable path.

Once the model is clean, I want to add a custom date slicer that lets users pick specific date ranges—month-to-month, quarter-to-quarter, or any ad-hoc span—without touching the underlying queries.

With a solid model and flexible date logic in place, the last step is a fresh Item Analysis dashboard that surfaces key KPIs: sales quantities, margin %, stock turn, and contribution by item category. Visuals should be clear, interactive, and perform smoothly on the Power BI Service.

Deliverables
• Re-engineered data model with conflict-free relationships
• Custom date-range slicer implemented with DAX or a dedicated Calendar table
• Item Analysis KPI dashboard, fully formatted and documented for hand-off

I’ll provide the current .pbix and source Excel files. Please keep all work inside Power BI Desktop, leverage native DAX functions, and note any assumptions directly in the file.