Context

Critical systems in application domains such as automotive, railway, aerospace, and healthcare are required to comply with safety standards. The understanding of the safety compliance needs specified in these standards can be difficult from their text. A possible solution is to use models.

Objective

We aim to evaluate the use of models to understand safety compliance needs.

Method

We have studied the effectiveness, efficiency, and perceived benefits in understanding these needs, with models and with the text of safety standards, by means of an experiment. The standards considered are DO-178C and EN 50128. We use SPEM-like diagrams to graphically represent the models.

Results

The mean effectiveness of 20 undergraduate students in understanding the needs and the mean efficiency were higher with models (22% and 38%, respectively), and the difference is statistically significant (p-value ≤ 0.02). Most of the students agreed upon the ease of understanding the structure of safety compliance needs with models when compared to the text, but on average, the students were undecided about whether the models are easy to understand or easier to understand than the text.

Conclusions

The results allow us to claim that the use of models can improve the understanding of safety compliance needs. Nonetheless, there seems to be room for improvement in relation to the perceived benefits. It must be noted that our conclusions may differ if the subjects were experienced practitioners.

中文翻译：

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对使用模型以提高对安全合规性需求的理解的经验评估

语境

需要在汽车，铁路，航空航天和医疗保健等应用领域中的关键系统符合安全标准。从它们的文本中很难理解这些标准中指定的安全合规性需求。一种可能的解决方案是使用模型。

目的

我们旨在评估模型的使用，以了解安全合规性需求。

方法

我们通过实验和模型以及安全标准文字研究了了解这些需求的有效性，效率和可感知的收益。所考虑的标准是DO-178C和EN50128。我们使用类似SPEM的图表以图形方式表示模型。

结果

使用模型，20名大学生理解需求的平均效率和平均效率较高（分别为22％和38％），差异具有统计学意义（p值≤0.02）。与课本相比，大多数学生都同意易于理解模型对安全合规性需求的结构，但是平均而言，学生们对模型是否比课本更容易理解还是不确定还不确定。

结论

结果使我们认为使用模型可以增进对安全合规性需求的理解。但是，在感知收益方面似乎仍有改进的空间。必须注意的是，如果受试者是经验丰富的从业者，我们的结论可能会有所不同。