Data-oriented vs Process-oriented
The philosophy that underlies the data oriented approach is that are stable and more unchanging than Processes can be revised with every reorganization. Data entities, on the other hand, rarely change in the lifetime of a business. Attributes of entities also rarely change. Even though the values of data do change constantly, the structure of the data does not. data are stable, then they should be examined closely and first.
Theories
- Data-oriented analysis is based mainly on theories about data.
- Semantic information theory: seeks to understand the meaning behind the data in applications and is most obvious in the depiction of meaning underlying entity relationship diagrams.
- Relational database theory is based on mathematical set theory (or relational calculus)
Process activities are based on the same systems theory which was the basis for the process development paradigm of Chapters 7 and 8.
Some problems with DFDs are:
- DFDs do not accommodate time.
- DFDs have no implied sequence to processing.
- DFDs assign media to data early in analysis without any real deliberation.
Business Area Analysis (BAA)
Main Tasks
- Data modeling
- Data analysis
- Functional decomposition (I.e., process modeling)
- Process dependency analysis
- Process data flow diagramming
- Process/data interaction mapping and analysis
In the end of the BAA, we should have a CRUD Matrix
Data Analysis
It is the last step, and analytics are used for the documentation
Data modeling
- Modeling data using ERDs and Normalization
- Modeling starts from unorganized data description, and then normalized and structured by setting the:
- Relationships
- Cardinalities
- Attributes
- Types of entities:
- Fundamental entity
- Attributive entity: derives the fundamental entity
- Associative entity: like junction table
- Normailziation methods:
- Direct methods
- Tabular method
Functional decomposition
- Business Functions are the main processes in the business and it consists of a group of activities
- Business Activities are procedures in the function (usually titled like so <Do-Something>
- Business Processes identifies the details of an activity
- Elementary process is a procedure that cannot be decomposed further without making the procedure lose its identity
- Process Dependency Diagram (PDD)
Decomposition results are used to develop a process dependency diagram.
A process dependency diagram, like an ERD for data, identifies the sequence and types of relationships between processes.
Process relationships describe logical connections that include cardinality, sequence, iteration, and selection components
- Process Data Flow Diagram (PDFD)
PDFD = PDD (Processes Depend. Dia.) + DFD (Data Flow Dia.)
Triggers in the PDFD:
- Process data triggers (or just data triggers):
- defined using small arrows
- when data comes, trigger a process
- Event trigger:
- defined using large arrows
