View DNDAF:OV-6b Operational State Transition Description Subview

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Title

OV-6b Operational State Transition Description Subview

Version & Date

1.6 See DNDAF Release History

Introduction

The OV-6b subview is part of the DNDAF Operational View.

The Operational View-6b (OV-6b): Operational State Transition Description is a graphical method of describing the dynamic behaviours of the operations that may not be adequately addressed by OV-5a and OV-5b. OV-6b addresses the critical sequencing behaviours of operational activities responding to various events. The operational state changes depending on the current state, the rule set and the triggers.

Purpose

The explicit sequencing of activities in response to external and internal events is not fully expressed in OV-5b. An Operational State Transition Description can be used to describe the explicit sequencing of the operational activities. 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 with respect to a specific operational node.

Background

Management needs to understand the governance elements that impact the architecture project. What are the “rules of engagement”? What constraints apply? Important characteristics of the architecture project are only discovered when its dynamic behaviours are defined and described. The dynamic behaviour concerns the timing and sequencing of events that capture the operational behaviour of a process.

Three types of models are needed to refine and extend the project architecture’s operational view to adequately describe the dynamic behaviour and performance characteristics of the architecture project. These three models are:

Software-based project architectures will typically use the suite of OV-6 sub-views to describe and define the pertinent operational rules. The OV-6a captures additional Concept of Operations information introduced by the Operational Process Model (OV-5b) and/or the Logical Data Model (OV-7).

The OV-6b sub-view 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). OV-6b is based on the state chart diagram.

Description

Definition

The Operational State Transition Description OV-6b is a graphical method of describing how an operational node or activity responds to various events by changing its state. The diagram represents the sets of events to which the architecture will 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.

State transitions in executable operational architectural models provide for descriptions of conditions that control the behaviour of process events in responding to inputs and in producing outputs. A state specifies the response of a process to events. The response may vary depending on the current state and the rule set or conditions. Distribution settings determine process time executions.

Detailed Description

The OV-6b sub-view relates states, events, and actions. A state and its associated action(s) specify the response of an operational activity to events. When an event occurs, the next state may vary depending on the current state (and its associated action), the event, and the rule set or guard conditions. A change of state is called a transition. Each transition specifies the response based on a specific event and the current state. Actions may be associated with a given state or with the transition between states.

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 and to expensive correction efforts.

Subview DADM Elements

The DADM entities and attributes provided below are the elements that this sub-view is responsible for creating:

 

 

Presentation

  • UML State Machine Diagram

Examples

See:

  • p66 Figure 3.12.1 in DND/CF Architecture Framework (DNDAF)  Volume 2: DND/CF Views and Sub-Views
  • p35 Figure 2.13.1 in DND/CF Architecture Framework (DNDAF) Volume 4: User Guide.

Prerequisites

The OV-5a and OV-6a are the prerequisites for this sub-view:

  • OV-5a. Actions in OV-6b map to operational activities in OV-5a.
  • OV-6a.A rule in OV-6a may define guard conditions for an action.

 

See DNDAF Subview Dependencies

 

Comments

 

Other Frameworks

See also:

References


Category:Framework -> Specification
Category:Framework -> Subview

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