7.Analysis Services – an analytical engine (MS SQL Server Analysis Services, or SSAS) that aggregates monthly (or weekly) data, stores it in a multidimensional model (OLAP cube) and transmits to the front-end application (Power Pivot for MS Excel). The cube has several dimensions, namely time, the ‘retail chain – store’ hierarchy, SKU category and others. Additionally, the engine calculates sophisticated KPIs – for example, sales growth in a particular store for a certain period of time.