A Multi-driven Approach to Improve Data Analytics for Multi-value Dimensions - New Contributions in Information Systems and Technologies - page 112

In FoC , the procedure price corresponds to the SUM of the base price as-
signed to each Lot within a Procedure . The proposal price corresponds to
the global price presented within the scope of a specific Proposal , which derives
from the granular prices expressed for each LOT in the corresponding Proposal .
In EoC , the price is established by comparing the contract price and the real total
price. The contract price is filled out in the Procurement Report by the contracting
authority when a public contract is awarded. The real total price is filled out in the
Final Works Report by the contracting authority when a public contract is executed.
During the contract execution phase, deviations to the contracted price can be formu-
lated based on multiple criteria, therefore the need to report all relevant events that
may contribute to justify any additional costs not considered in the negotiation phase.

3.2 Problem Statement

The implementation of the OOP-DW followed a multi-driven approach to data model-
ling which integrates three existing approaches normally used separately: goal-driven,
user-driven and data-driven [14]; and two approaches usually not used in data
warehousing field: process-driven and technology-driven.
In the data-driven approach we tried to construct the DW data models based only
on operational system database schemas overlooking business goals and user needs.
The goal-driven data modelling helped us to form the data models taking into consid-
eration business goals and accorded business processes, ignoring data sources and
user needs. Finally, by combining the principles from the user-driven data modelling,
it was possible to complement the derived data models directly from user query
requirements.
The process-driven approach enabled us to propose improvements (by using and
creating subject oriented enterprise data schema) to satisfy Key Performance Indica-
tors - KPI [15]. The technology-driven approach is an enabler that we had to consider
in designing the DW schema; existing technological capabilities in the organization to
implementing the DW solution became an obstacle that needed to be considered. The
paper provides a special emphasis to this approach because it is not well documented
in the literature and because it was a challenge to the implementation of the OOP-DW
using the Pentaho-Mondrian opensource tool [16].
The OOP-DW had to comply with business requirements and policies related to
public procurement forcing the specification of multi-valued dimensions for the
following two dimensions.

• Contracting Entity , in a public procurement it is possible to find situ-

ations where two or more public entities participate together in the statement
of a Procedure , for which entities can create a consortium to present a
joined project Proposal . Since a Procedure can include heterogeneous
projects, the usual process is to segment the Procedure into a set of smaller
projects named Lots , each one with a regional or national coverage. Because
of business policies, weighting the participation of each Contracting entity
in a Lot/Procedure is not an option, originating non-strictness situations;