Context:

Requirements engineering and software architecture are tightly linked disciplines. The Twin Peaks model suggests that requirements and architectural components should stay aligned while the system is designed and as the level of detail increases. Unfortunately, this is hardly the case in practical settings.

Objective:

We surmise that a reason for the absence of conjoint evolution is that existing models, such as the Twin Peaks, do not provide concrete guidance for practitioners. We propose the Requirements Engineering for Software Architecture (RE4SA) model to assist in analyzing the alignment and the granularity of functional requirements and architectural components.

Methods:

After detailing the RE4SA model in notation-independent terms, we propose a concrete instance, called RE4SA-Agile, that connects common artifacts in agile development, such as user stories and features. We introduce metrics that measure the alignment between the requirements and architecture, and we define granularity smells to pinpoint situation in which the granularity of one high-level requirement or high-level component is not uniform with the norm. We show two applications of RE4SA-Agile, including the use of the metrics, to real-world case studies.

Results:

Our applications of RE4SA-Agile, which were discussed with representatives from the development teams, prove to be able to pinpoint problematic situations regarding the relationship between functional requirements and architecture.

Conclusion:

RE4SA and its metrics can be seen as a first attempt to provide a concrete approach for supporting the application of the Twin Peaks model. We expect future research to apply our metrics to additional cases and to provide variants for RE4SA that support different concrete notations, and extend the perspective beyond the functional perspective of this research, similar to what we did with RE4SA-Agile in this paper.

中文翻译：

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敏捷开发中需求和体系结构的一致性和粒度：功能视角

内容：

需求工程和软件体系结构是紧密联系的学科。Twin Peaks模型建议在设计系统时以及随着详细程度的提高，需求和体系结构组件应保持一致。不幸的是，在实际环境中几乎不是这种情况。

目的：

我们推测缺少联合进化的原因是现有模型（例如双峰）没有为从业人员提供具体指导。我们提出了软件体系结构需求工程（RE4SA）模型，以帮助分析功能需求和体系结构组件的一致性和粒度。

方法：

在以符号无关的术语详细描述了RE4SA模型之后，我们提出了一个称为RE4SA-Agile的具体实例，该实例连接了敏捷开发中的常见工件，例如用户故事和功能。我们引入了度量来度量需求和体系结构之间的一致性的度量，并定义了粒度气味，以查明一种高级需求或高级组件的粒度与规范不一致的情况。我们展示了RE4SA-Agile在实际案例研究中的两种应用，包括指标的使用。

结果：

与开发团队的代表进行了讨论，我们的RE4SA-Agile应用得以证明能够查明与功能需求和架构之间的关系有关的问题情况。

结论：

RE4SA及其度量标准可以看作是首次尝试提供具体方法来支持Twin Peaks模型的应用。我们希望将来的研究将我们的指标应用于其他情况，并为RE4SA提供变体，以支持不同的具体符号，并将其范围扩展到本研究的功能范围之外，类似于我们对RE4SA-Agile所做的操作。