System Views (SV) [Physical, Specification or Solution Views]
SV-10a Resource Constraints Specification v1.2
The purpose of this Product is to specify functional and non-functional constraints on the implementation aspects of the architecture (i.e. the structural and behavioural elements of the SV viewpoint).
Background:
SV-10a describes constraints on the resources, functions, data and ports that make up the SV physical architecture. The constraints are specified in text and may be functional or structural (i.e. non-functional).
Usage:
- Definition of implementation logic
- Identification of resource constraints
Data objects:
The data in an SV-10a can include:
- Resource Constraint
Representation:
- Text (preferably specified in a computer-interpretable constraint language such as OCL)
- Tabular
Detailed Product Description:
The Resource Constraints Specification describes the rules that control, constrain or otherwise guide the implementation aspects of the architecture. Resource Constraints are statements that define or constrain some aspect of the business, and may be applied to:
- Resources
- Resource Interactions
- Functions
- System Ports
- System Port Connections
- Data Elements
An SV-10a Presented in Tabular Form
In contrast to the Operational Rules Model (OV-6a), SV-10a focuses physical and data constraints rather than business rules.
MODAF categorises Resource Constraints as follows:
- Structural Assertions – non-functional constraints governing some physical aspect of the architecture.
- Action Assertions – functional constraints governing the behaviour of resources, their interactions and data exchanges.
- Derivations – these involve algorithms used to compute facts.
Where a Resource Constraint is based on some standard, then that standard should be listed in the Standards Profile (TV-1).
Some Resource Constraints can be added as annotations to other views. SV-10a then should provide a listing of the complete set of rules with a reference to any views that they affect.
With potentially complex Resource Constraints it may be more useful to express these rules in Object Constraint Language (OCL). Whichever language is used to describe the constraints, it will be referenced and well documented (i.e., there will be text books or articles that describe it and provide examples of its use).
Example SV-4 with SV-10a OCL Constraints Embedded in Functions
Page version 1.2, dated 1st July 2008