UML Sequence Diagrams
During the requirements analysis phase, the system can be treated as a single "black box", which means that we can look at the system's behavior (what it does) without explaining how it does it. Read this section to see an example of a simplified trace diagram
that shows only system input events. This is called a system sequence diagram.
12. Documenting Contracts
Suggested schema by Liu, for presenting a contract is as shown in Table 3.11:
Table 3.11: Schema for Documenting a Contract of a System Operation
Name | Name of a system operation and parameters |
Responsibilities | A short description of the responsibility the operation |
Type | Name of type (concept, software class, interface) |
Cross References S | System function reference numbers, use cases, etc |
Note | Design notes, algorithms, and so on |
Exceptions | Exceptional cases |
Output | Non-User Interface (UI) outputs, such as messages or records that are sent outside of the system |
Pre-conditions | The conditions that the state of the system is assumed to satisfy before the execution of the operation |
Post-conditions | Describes changes in the state of objects in the domain area. The state changes can include: instances creation, associations formed or deletion and attributes changed. |