Start of the Current Physical Dataflow Model for the Feasibility Study (slide 17)
Current Physical Dataflow Model
For the As-Is business system, the dataflow model comprises:
- A Context diagram showing the area under study and its external communication.
- A set of Dataflow diagrams showing a hierarchy of more and more detailed decompositions of the in-scope processes.
- A set of Elementary Process Descriptions for each bottom-level process (i.e one not further decomposed). This includes volumetrics and any hardware and software that currently provides support.
- A set of descriptions for each dataflow that crosses the scoping boundary (aka I/O Descriptions)
- Descriptions for each datastore and a cross-reference to the entities (from the LDS) it contains.
This is a warts-and-all view. For example, you'll likely find entities appearing in more than one datastore. Another likely find will be processes that only exist because of how things are presently done - you'll be able to largely ignore any of these.
Don't be too pedantic with the Current Physical - it's only a route to get to a logical view of the current services.
For more about dataflow models, see Dataflow Modelling (opens in a new window)
It has been cross checked for completeness against the Logical Data Model (do all LDM entities appear in datastores and move in dataflows?) and used to identify the main business events for the Event Catalogue (what happens in the real world that causes a flow into a datastore?).
It will be updated as the feasibility study continues.