P8 — Resource Constraints

Purpose & Usage

The P8 Viewpoint is concerned with Identification and description of Resources Constraints and Resource Requirements

• Non -Functional Requirements.
• Safety Cases.
• Definition of implementation logic.
• Identification of resource constraints.

Scope

• Shall contain Resource Requirements that relate to Resource Constraints relevant for the entity of interest.
• Shall contain Physical Active Resources, Physical Behaviour and Physical Passive Resources that these Resource Constraints or Resource Requirements apply to.
• May show Resource Specifications that group Resource Constraints and Resource Requirements.
• May show Resource Rationale relating to Resource Constraints.
• May trace Resource Rationale to Logical Constraints.

Representation

• Text Document
• Tabular.
• Parametric diagram.

Cut-out (Meta-model)

flowchart TB
    LogicalConstraint["Logical Constraint"]:::activity
    ResourceRationale["Resource Rationale"]:::config
    PAR["Physical Active Resource"]:::config
    PBehavior["Physical Behavior"]:::config
    PPR["Physical Passive Resource"]:::config
    RC["Resource Constraint"]:::config
    RReq["Resource Requirement"]:::config
    RSpec["Resource Specification"]:::config
    ResourceRationale -->|"originates from"| LogicalConstraint
    RC -->|"originates from"| ResourceRationale
    RSpec -->|"aggregates"| RC
    RSpec -->|"aggregates"| RReq
    RReq -->|"relates to"| RC
    RC -->|"applies to"| PAR
    RC -->|"applies to"| PBehavior
    RC -->|"applies to"| PPR
    RReq -->|"applies to"| PAR
    classDef activity fill:#9DC3E6,stroke:#1F4E79,color:#000
    classDef config fill:#F4B084,stroke:#833C0C,color:#000

NAFv4 Compliant Example

flowchart LR
    IP66["«Resource Requirement» IP66"]:::config
    NATOSec["«Resource Requirement» Certified NATO Secret"]:::config
    Cont["«Resource Requirement» 24/7 Continuous Operation"]:::config
    IP6x["«Resource Constraint» IP6x"]:::config
    CommDev["«Physical Active Resource» Communication Device"]:::config
    Tactical["«Resource Function» Conduct Tactical Response"]:::config
    IP66 -->|"relates to"| IP6x
    IP6x -->|"applies to"| CommDev
    IP66 -->|"applies to"| CommDev
    NATOSec -->|"applies to"| CommDev
    Cont -->|"applies to"| Tactical
    classDef config fill:#F4B084,stroke:#833C0C,color:#000

Notes on the Example

Requirements Engineering is a continuous activity, any P8 output would therefore be a snapshot and be subject to change. IP6x denotes the constraint, the general Ingress Protection standard family, and implies for a this communication device it needs to be dust -tight (the highest rating). IP66 defines a specific, compliant Resource Requirement derived from that constraint.