Reactive systems with a large degree of human interaction can be vulnerable to off-nominal behaviors (ONBs) that arise from the human operator’s unpredictability. In prior research, we have addressed the ONB problems by developing an approach to translating a set of reactive requirements into the rule-based causal component model (CCM). The CCM’s analysis involved expanding the CCM rules into a larger set of rules that encompass the system’s entire state space, displaying both nominal and off-nominal behaviors as transition paths. However, a major limitation of CCM is the potential for state explosion, which grows as a function of the system’s component states. In this paper, we introduce the causal scenario model (CSM), which uses the same rule-based approach, while addressing the state explosion problem associated with CCM. The CSM grows as a function of system components and provides a visually concise alternative to CCM, while still providing information useful in the exposing and addressing of ONBs during the requirements analysis phase. We introduce CSM and demonstrate the effectiveness of CSM, using a case study that would be more difficult to visualize using CCM, and most other state-based modeling techniques.

中文翻译：

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在一组反应性需求中可视化非名义行为时解决状态爆炸问题

具有大量人类交互的反应式系统可能容易受到由人类操作员的不可预测性引起的非名义行为 (ONB) 的影响。在之前的研究中，我们通过开发一种将一组反应性需求转换为基于规则的因果组件模型 (CCM) 的方法来解决 ONB 问题。CCM 的分析涉及将 CCM 规则扩展为包含系统整个状态空间的更大规则集，将标称和非标称行为显示为转换路径。然而，CCM 的一个主要限制是状态爆炸的可能性，它随着系统组件状态的变化而增长。在本文中，我们介绍了因果场景模型 (CSM)，它使用相同的基于规则的方法，同时解决了与 CCM 相关的状态爆炸问题。CSM 作为系统组件的功能而增长，并为 CCM 提供了视觉上简洁的替代方案，同时仍然提供在需求分析阶段对 ONB 的公开和寻址有用的信息。我们介绍了 CSM 并演示了 CSM 的有效性，使用一个案例研究，使用 CCM 和大多数其他基于状态的建模技术将更难以可视化。