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Exercise No. 9: Sales Process (apa)

As the result of DFM Case "sales process" this cube stores data about a sales process.

We have four dimensions with the following hierarchical structure:

Table A.E.4.1 - sales process

Please build the Aggregation Path Array and assume the following end-user requirements:

1) "a complete drill-down by the time dimension down to month for each sales department on a product group, irrespective of the customer the product is sold to"

2) "a monthly report for each product group independent of the customer and the sales department"

Select the corresponding cells in the APA and choose the cubes to materialize, then highlight the derivatives of those cubes.

Solution

Figure A.E.3.1 - The resulting APA with the redundancy free-set highlighted

Size of the redundancy-free set (including the base cube): 72

Required cubes, the materialization decision and derivatives

The blue area represents the end-user requirement 1 ("a complete drill-down by the time dimension down to month for each sales department on a product group, irrespective of the customer the product is sold to") and requirement 2 ("a monthly report for each product group independent of the customer and the sales department").

Materializing cube v = (C_*,P_gr,S_sd,T_m) (dark blue cell "T_m", representing end-user requirement 1) and cube w = (C_*,P_gr,S_*,T_m) (dark green cell "T_m", representing end-user requirement 2) offer us the following sets of derivatives.

Figure A.E.3.2 - Derivatives of cube v = (C_*,P_gr,S_sd,T_m)

Figure A.E.3.3 - Derivatives of cube w = (C_*,P_gr,S_*,T_m)

Figures A.E.3.2 and A.E.3.3 show that end-user requirement 2 is covered by the derivatives of v. Considering that w = (C_*,P_gr,S_*,T_m) can easily be derived from v = (C_*,P_gr,S_sd,T_m) by aggregation along only one dimension simplifies the materialization decision:

To meet all end-user requirements we will only have to materialize the cube v.

This exercise is part of a case study: dfm - apa log