Remarks: This document is part of the QP/C Certification Kit↑ , which has been specifically designed to help companies in safety certification of their software based on the QP/C 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/C 7.4.0.

Purpose and Scope

This Software Architecture Specification (SAS) with Unique Identifier: DOC_SAS_QP describes the software architecture of QP/C Framework that satisfies the QP Software Requirements Specification (DOC_SRS_QP) and the QP Software Safety Requirements Specification (DOC_SSR_QP). By presenting a compliant Safety Viewpoint, this Software Architecture Specification also aims to achieve the required safety integrity levels:

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

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

Architectural Viewpoints

The QP/C 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/C Applications based on the QP/C 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/C Framework and QP/C Application;
the interface between QP/C Framework and the QP/C Application based on the framework as well as between QP/C 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 @QPX Framework or 'QA' for @QPX Application)
 |  |   +--------- [3] Architecture view (e.g., 'OSAL' for OS Abstraction Layer)
 |  |   |
SAS_QP_view

Examples: SAS_QP_OSAL, SAS_QP_OO

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]. 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

Technology Viewpoint