Table A.E.6.1 - Supply process

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

1) "a monthly and quarterly report for each item type independent of the supplier and the procurement department"

2) "a complete drill-down by the time dimension down to month for each supplier on an item type, irrespective of the employee"

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

Figure A.E.6.1 - 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 monthly and quarterly report for each item type independent of the supplier and the procurement department") and requirement 2 ("a complete drill-down by the time dimension down to month for each supplier on an item type, irrespective of the employee").

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

Figure A.E.6.2 - Derivatives of cube v = (S_*,I_ty,E_*,T_m)

Figure A.E.6.3 - Derivatives of cube w = (S_su,I_ty,E_*,T_m)

Figures A.E.6.2 and A.E.6.3 show that end-user requirement 1 is covered by the derivatives of w. Considering that v = (S_*,I_ty,E_*,T_m) can easily be derived from w = (S_su,I_ty,E_*,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 w.