Logical Definition

Logical definition is the most essential aspect of any approach to managing data and, therefore, managing change in business systems. Put simply, it is ‘the glue which holds everything together’ – i.e. which allows the existing to be fully understood, and the proposed to be stated unambiguously, in the same objective and meaningful context.​

If applied as it is within the Change Management Model, logical definition allows you to establish the commonality or disparity between physical data elements and, in turn, between business activities. It also provides useful references for understanding and communicating business concepts; especially those which are not present in existing applications.​

Poor data quality is far more likely to result from data which is missing than data which is present but incorrect. Further, the logical constructs implicit in existing applications are not always an accurate reflection of the intended, or even stated, business logic. Where they are too simplistic, due to missing attributes and/or constraints, they may fail to illustrate the true nature of business entities.​

So logical analyses must be performed both ‘ground-up’ and ‘top-down’. The ‘ground-up’ approach is purely methodical, and involves defining logical data elements which are represented by all of the existing physical data elements. The ‘top-down’ approach is purely conceptual, and involves defining logical data elements for data which is being generated by business activities, but not captured. This includes establishing all of the ways in which data needs to be classified in order to facilitate its integration for the purposes of Business Intelligence.​

Generally, the need to define business entities, attributes and domain values – i.e. describe them in a logical, objective and meaningful way - requires an analyst to think conceptually and sometimes challenge existing perceptions. Therefore, whilst great depth of experience within the relevant business sector is likely to expedite the task, great breadth of experience across many different sectors may prove to be just as valuable.