您将学到什么：
- 如何弥合需求，体系结构，设计，验证和验证之间的差距。
- How to use requirements management to support ISO 26262 standards.
ISO 26262标准规定，功能安全评估者应考虑是否有足够的要求管理（包括双向可追溯性）实施。该标准未指定评估者应如何完成此任务。但是，可以合理地假设需求和实施之间的连接子集有限，这可能不会引起预期。
An apparently simple requirement from a customer, such as “The software interface of the device should be compliant in all respects with specification ABCD-123, except where explicitly noted elsewhere in these requirements,” expands into a very complex set of requirements when fully elaborated.
建筑师和设计团队如何在一系列规格和要求列表中有效地管理这种可追溯性？他们如何确保在开发周期的每个步骤中建立和测试的内容都与原始要求联系起来（图。1）？这尤其具有挑战性，因为需求，架构，设计，验证和验证之间的交接取决于人类的解释，以弥合这些步骤之间的差距。
可追溯性的默认方法
实现可追溯性的最明显方法是通过矩阵，无论是在Jama Connect等专用工具还是Excel电子表格中实施。每行的一项要求，也许是层次结构的，拥有所有权，来源参考，实施参考，状态等。该矩阵是双向参考。
矩阵相对较小时可以很好地工作。也许建筑师将它们分为子团队，并分配对集成符检查子矩阵和系统矩阵之间对应的责任。
Matrices become unmanageable, though, when the number of requirements moves into the thousands. A matrix provides a disciplined way to organize data, but it doesn’t provide automation. Ensuring correspondence between requirements and implementation is still a manual task.
自动化的第一步
The core problem is connecting between domains that speak very different languages: requirements management, documentation, chip assembly, verification, and hardware/software interface (HSI) descriptions. One approach common in software and mechanical systems is through application-lifecycle-management (ALM) or product-lifecycle-management (PLM) solutions, where all development tools are offered under a common umbrella by a single provider. With that level of control, an ALM or PLM could manage traceability in data between these domains.
However, it’s difficult to see how that kind of integration could work with electronic-design-automation (EDA) tool flows, where the overriding priority is to stay current with leading technologies and complexities. System-on-chip (SoC) development teams demand best-in-class flows and are unlikely to settle for solutions offering traceability at the expense of lower capability.
第二种方法扩大范围的要求s-management tools by connecting to data assets within implementation files. Requirements tools naturally have no semantic understanding of these foreign objects, so all responsibility to capture, check, and maintain these links still rests entirely with the SoC development team. Tracing is simplified under a common interface, but the approach doesn’t significantly reduce manual effort or opportunity for errors in creation or maintenance.
语义意识的可追溯性链接
有效的自动化需要每个域中的语义理解水平：需求，组装，文档和HSI。没有必要理解所有可能的对象，只有可能通过要求引用的对象。标准有助于“一流的”兼容性：REQIF的要求，用于文档的DITA和用于组装的IP-XACT（XML格式）和HSI。类似的工具大动脉的和谐痕迹can tie all this together（图2）。
Trace links should connect to meaningful objects – a requirement object, a port width, an IP version, and configuration or a register offset. Rather than file and line number links, these can move around as requirements, implementation, and verification evolve and remain valid. Some effort is required to establish links at the outset, but checking the impact of changes is automatic after that.
此外，有机会从数据中得出许多链接。在IP-XACT中，此类对象很容易找到。有了更多的智能，也可以在文档和需求描述中找到它们。
语义连通性简化了检查问题和诊断问题的完整性。随着开发从概念到建筑师的发展，然后通过单元测试，系统测试和V开发流中的完整系统验证，浮动或不完整的链接立即变得明显，无论是从需求，实施或文档中来看。该问题的根源也很明显。此外，客户或审计师可以立即看到证据表明合规实施符合要求。
