Remarks: This document is part of the QP Certification Kit↑, which has been specifically designed to help companies in safety certification of their software based on the QP Framework treated as commercial off-the-shelf (COTS) software.

Revision History

QP version	Document revision	Date (YYYY-MM-DD)	By	Description
7.3.4	A	2024-05-05	MMS	Initial release for IEC-61508 SIL-3 and IEC-62304 Class-C.
7.4.0	A	2024-07-30	MMS	Updated for QP 7.4.0.

Purpose and Scope

This Software Architecture Specification (SAS) with Unique Identifier: DOC_SAS_QP, describes the software architecture of QP Framework and QP Applications. The main objective of this Software Architecture Specification is to present the software architecture that satisfies both QP Software Requirements Specification (DOC_SRS_QP) and QP Software Safety Requirements Specification (DOC_SSR_QP) to achieve the required safety integrity levels:

IEC 61508 SIL 3
IEC 62304 Class C
ISO 26262 ASIL D

Remarks: This document is also the best source of information about the master plan for the overall organization of QP Framework as well as QP Applications derived from the framework. The detailed QP Framework design is described in a separate document: QP Software Design Specification [DOC_SDS_QP].

Architectural Viewpoints

The QP Framework architecture is presented according to the international standard [ISO-42010:2022] Architecture Description by means of the following architectural viewpoints, each consisting of various architectural views:

Stakeholders

This Software Architecture Specification is primarily intended for the following stakeholders:

Application Developers who develop QP Applications based on the QP Framework,
Software Architects,
Quality-Assurance Engineers,
System Engineers,
Test Engineers, as well as
Managers who oversee the software development.

Concerns

This architecture specification addresses the following general concerns (understood here as topics of interest [ISO-42010:2022]):

the applied programming paradigms and software technologies;
the context, layering, and assignment of functionality to QP Framework and QP Application;
the interface between QP Framework and the QP Application based on the framework as well as between QP Framework and the Operating System underlying the framework;
main policies with respect to resource management and ownership.

Document Conventions

Architecture Specification UIDs

For traceability, this Software Architecture Specification uses the Unique Identifiers (UIDs) with the following structure:

 +---------------- [1] Work artifact class (e.g., 'SAS' for Software Architecture Specification)
 |  +------------- [2] Project identifier ('QP' for QP Framework or 'QA' for QP Application)
 |  |   +--------- [3] Viewpoint ID (e.g., 'TECH' for Technology viewpoint)
 |  |   |  +-------[4] View ID (e.g., 'OO' for object-oriented view)
SAS_QP_vp_view

Examples: SAS_QP_TECH_OO, SAS_QP_COMP_CLS

UML Semantics

Most diagrams presented in this Software Architecture Specification conform to the the established and precisely defined semantics of the Unified Modeling Language [UML2.5:17], [UML-Dist:04]. In case a diagram uses any "non-normative" elements, the semantics of those are explained in the diagram description.

References

[ISO-42010:2022]	ISO/IEC/IEEE, "International Standard ISO/IEC/IEEE 4210, Software, systems and enterprise engineering - Architecture description", 2022
[DOC_SRS_QP]	Software Requirements Specification
[DOC_SSR_QP]	Software Safety Requirements
[DOC_SDS_QP]	Software Design Specification
[QM-Tool:2024]	Quantum Leaps, QM Model-Based Design Tool↑
[OO-in-C:2023]	Object-Oriented Programming in C↑, Quantum Leaps, GitHub, 2023
[UML2.5:17]	"OMG Unified Modeling Language (OMG UML) Version 2.5.1", document formal/2017-12-05, OMG 2017
[UML-Dist:04]	Martin Fowler, "UML Distilled, 3rd Edition", Addison-Wesley, 2004

Technology Viewpoint