DoDAF Viewpoints and Models
OV-6b: State Transition Description.
The OV-6b is a graphical method of describing how an Operational Activity responds to various events by changing its state. The diagram represents the sets of events to which the Activities respond (by taking an action to move to a new state) as a function of its current state. Each transition specifies an event and an action.
An OV-6b can be used to describe the detailed sequencing of activities or work flow in the business process. The OV-6b is particularly useful for describing critical sequencing of behaviors and timing of operational activities that cannot be adequately described in the OV-5b Operational Activity Model. The OV-6b relates events and states. A change of state is called a transition. Actions may be associated with a given state or with the transition between states in response to stimuli (e.g., triggers and events).
The intended usage of the OV-6b includes:
- Analysis of business events.
- Behavioral analysis.
- Identification of constraints.
The OV-6b reflects the fact that the explicit sequencing of activities in response to external and internal events is not fully expressed in OV-5a Operational Activity Decomposition Tree or OV-5b Operational Activity Model. Alternatively, OV-6b can be used to reflect the explicit sequencing of actions internal to a single Operational Activity or the sequencing of operational activities. OV-6b is based on the statechart diagram. A state machine is defined as "a specification that describes all possible behaviors of some dynamic view element. Behavior is viewed as a traversal of a graph of state interconnected by one or more joined transition arcs that are triggered by the dispatching of a series of event instances. During this traversal, the state machine executes a series of actions associated with various elements of the state machine."
State chart diagrams can be unambiguously converted to structured textual rules that specify timing aspects of operational events and the responses to these events, with no loss of meaning. However, the graphical form of the state diagrams can often allow quick analysis of the completeness of the rule set, and detection of dead ends or missing conditions. These errors, if not detected early during the operational analysis phase, can often lead to serious behavioral errors in fielded systems or to expensive correction efforts.
States in an OV-6b may be nested. This enables quite complex models to be created to represent operational behavior.
OV-1: High-Level Operational Concept Graphic
OV-2: Operational Resource Flow Description
OV-3: Operational Resource Flow Matrix
OV-4: Organizational Relationships Chart
OV-5a: Operational Activity Decomposition Tree
OV-5b: Operational Activity Model
OV-6a, 6b, 6c: Introduction
OV-6a: Operational Rules Model
OV-6b: State Transition Description
OV-6c: Event-Trace Description