Retail analytics case study
A €731K revenue decline at a 20-store retailer, traced from raw data to root causes, management decisions, early warning, a 13-week forecast and an evidence-grounded AI assistant.
H2 2024 net revenue €10,188,727.55; H2 2025 net revenue €9,457,457.05.
Brightwater Retail runs 20 stores in Ireland. In the second half of 2025, net revenue fell against the same period of 2024. Management asked three questions:
The hard part is not finding a number that moved. It is separating what the data proves from what it only suggests, so that money is spent fixing real causes rather than guesses.
Stores S03, S04 and S05 lost about 27.8% of their transactions, against 1.1% for matched controls. A difference-in-differences estimate puts the excess decline at €397,778 (54% of the total), range €377,245 to €435,210. Footfall, competitor and store-operations data were not available, so the cause is not established.
Electronics & Tech availability fell from 95.4% to 89.3%, mostly on Voltix-supplied products. Estimated lost sales were about €37,235 gross and €23,963 net (range €23,963 to €44,460). Whether the supplier or the retailer's ordering is responsible is not established.
Refunds recorded with the till reason “Faulty” rose by €31,589 (+90%), concentrated in five stores. A till reason is not a verified defect; QA and batch data would be needed.
The discount rate rose from about 2.4% to 11.9%. Four estimation methods disagree in sign, so they are reported separately and never added together.
Financial size sets investigation priority; evidence strength sets what action is justified.
Nine report pages, generated from code and validated in Power BI Desktop. Select a page to enlarge it.
Explore the interactive dashboard
A print-ready Executive KPI Summary built in Power BI Report Builder on the SQL Server warehouse. It reads thin views over the governed KPI layer, takes cascading Year/Half parameters and a store parameter, and opens with a validation gate (reconciliation 45/45, KPI validation 38/38). The H2 2025 export reconciles to €9,457,457.05 (−7.18%), and the store rows sum to the estate total.
Open the PDF report (2 pages) Download Excel
Other period: H1 2025 (PDF · Excel), net revenue €8,629,984.78 (+1.438% vs H1 2024).
Data Analyst based in Dublin, open to Data Analyst and BI Analyst roles in Ireland.