Logical Data Model section introduction, Feasibility Study stage (slide 24)
We're at the point in the Acme Fashion case study of having just received signoff for the Terms of Reference. This gives the authority for the project to start. In our case, this is with a Feasibility Study.
For no particular reason, we'll look at the in-progress logical data model product first. You'll be developing this in conjunction with the Dataflow Model, a few slides later and updating it as you work on other products for the feasibility study.
As a reminder the logical data model comprises:
- A Logical Data structure (LDS) diagram showing the business entities and their direct relationships with each other (aka Entity Relationship Diagram or ERD)
- A set of relationship descriptors (usually on the diagram and further described with volumes and user role owner)
- A set of entity descriptions for the business entities on the LDS, consisting of a list of data items and their descriptions, with keys and optionality identified.
Completeness and Consistency
The one you'll see has been cross checked for completeness and consistency against dataflows and datastores in the Dataflow Model and events in the Event Catalogue.