State Table And State Diagram
State tables and state diagrams are data models employed in business analysis to illustrate the valid states an object can be in, along with permissible transitions between those states. These objects could range from business data items to any other piece of information that is crucial when dissecting a solution. Both models serve to clarify all possible states a single object can assume and the rules for transitioning between states.
Characteristics of State Tables
A state table is generally organized in a tabular format where both rows and columns represent the possible states of an object. The intersections or cells of the table indicate the transition from the state denoted by the row to the state indicated by the column. If a transition is not permitted, the corresponding cell is generally marked with an "X," "N/A," or "no." Conversely, allowable transitions are marked with a "yes" or may contain a description of the event triggering the transition. State tables are particularly useful in ensuring completeness, as they compel the business analyst to systematically evaluate every potential transition between states.
Example
| Initiated | Processed | Verified | Completed | Archived | |
|---|---|---|---|---|---|
| Initiated | - | ✓ | - | - | - |
| Processed | - | - | ✓ | - | - |
| Verified | - | - | - | ✓ | - |
| Completed | - | - | - | - | ✓ |
| Archived | ✓ | - | - | - | - |
Characteristics of State Diagrams
State diagrams, by contrast, offer a more visual representation. They employ ovals to represent states, and lines with arrows to indicate the transitions between states, sometimes labeled with the event that triggers the transition. Unlike state tables that show all possible transitions, including those that are not allowed, state diagrams present only the valid transitions, making it more straightforward for stakeholders to understand the flow. However, the visual nature of state diagrams could lead to a higher risk of missing out on some transitions.
Example
Use Cases
Both state tables and state diagrams are highly beneficial for solutions involving workflows, like an approval process. They are instrumental in uncovering business rules related to transitions between different states of an object. State tables offer the advantage of ensuring that all possible transitions are covered. In contrast, state diagrams are more effective in offering stakeholders a quick and intuitive understanding of valid transitions.
Relationship to Requirements
While both state tables and state diagrams are standalone models, they are not always sufficient for capturing highly complex transition events. In such scenarios, additional details might be documented outside the model. They serve to confirm or identify gaps in data and processes that other models may have specified. They are frequently used to model business rules and do not necessarily require additional requirements statements for correct development and testing.
Completeness and Visualization
In summary, state tables are more exhaustive in representing every possible transition, making them less prone to oversight. State diagrams, while easier to understand at a glance, might require extra diligence to ensure they are comprehensive.
By employing state tables and state diagrams meticulously, business analysts can specify the life cycle of an object in the solution space comprehensively and visually, thereby contributing to a more robust and reliable business solution.