Customizing the Dimensional Warehouse Model

When customizing the Dimensional Warehouse Model (DWM) in the context of an analytical project, you look at your scoped analytical requirements. Alternatively, if the entry point to the DWM is to identify and store data required for more complex applications such as risk calculations, the terms documented in the supportive content should be your starting point. For each requirement, you identify the fact entities and dimension entities that represent it in DWM by applying dimensional modeling techniques and by using the analytical requirements definition. Identify the existing DWM fact entities, measure attributes, dimension entities, and dimension entity attributes that are relevant to the project. Modify them if needed, and create new ones when they do not exist. This results in a customized project DWM that structures your business terminology and provides a solid foundation for building your dimensional IT assets.

Before you begin

The terms in scope of your project must be defined.
The practitioner version of the DWM must be available.

About this task

The purpose of this task is to review in detail all DWM elements that have been included in the scope of the project, because they have been mapped to the IGC terms, and to create new elements in the DWM, that provide the dimensional structures that are required to represent the new analytical requirements. When customizing the DWM, which holds dimensional structures that represent an enterprise-wide view of the business, consider a broader (enterprise-wide) perspective of the business, rather than just the particular project scope.

When customizing the DWM, for each scoped requirement, maintain your entities and packages, and create a DWM practitioner version.

Procedure

Maintain the entities into of your practitioner DWM. See Maintaining DWM entities using DWM.
Version your practitioner DWM. See Versioning data models.

Maintaining DWM entities
When maintaining Dimensional Warehouse Model (DWM) entities in the context of a project, you look at a requirement, identify the fact entities and the dimension entities that represent it in DWM, and review their definitions. Fact entities that are already mapped to the terms are directly identified. When needed, you create or update fact entities and you map them to your terms to keep the trace between DWM and the requirements. Reuse the existing conformed dimensions and link them to your fact entities. Optionally, create or update dimension entities. Maintain your project scope in DWM with the fact entities and the dimension entities that correspond to your scoped requirements.
Maintaining packages
When maintaining Dimensional Warehouse Model (DWM) packages, create or update a package as required by a new or updated fact entity. Optionally, you can create subpackages to organize your fact entities within a root package. As a rule, do not create or update the description of a package, as the delivered IIW supports most of your packages. The maintenance of fact entities triggers the maintenance of packages.

Parent topic: Developing the Dimensional Warehouse Model