System design is recognized as one of the most critical components of a software system that bridges system requirements and coding. System design also has a significant impact on testing and maintenance activities, and on further improvements during the lifespan of the software system. Software design should reflect all necessary components of the requirements in a clear and understandable manner by all stakeholders of the software system. To distinguish system elements, separation of concerns in software design is suggested. In this respect, identification of the user tasks, i.e., the tasks that need to be performed by the user, is not currently reflected explicitly in system design documents. Our main assumption in this study is that software quality can be improved significantly by clearly identifying the user tasks from those that need to be performed by the computer system itself. Additionally, what we propose has the potential to better reflect the user requirements and main objectives of the system on the software design and thereby to improve software quality. The main aim of this study is to introduce a novel notation for software developers in the frame of UML Activity Diagram (UML-AD) that enables designers to identify the user tasks and define them separately from the system tasks. For this purpose, an extension of UML-AD, named UML-ADE (UML-Activity Diagram Extended) was proposed. Afterwards, it was implemented in a serious game case for which the specification of user tasks is extremely important. Finally, its effectiveness was analyzed and compared to UML-AD experimentally with 72 participants. The defect detection performance of the participants on both diagrams with two real-life serious game scenarios was evaluated. Results show a higher level of understandability for those using UML-ADE, which in turn may indicate a better design and higher software quality. The results encourage researchers to develop specific design representations dedicated to task design to improve system quality and to conduct further evaluations of the impact of these design on each of the above mentioned potential benefits for the software systems.

中文翻译：

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用于改进软件设计的用户任务设计符号

系统设计被认为是桥接系统需求和编码的软件系统的最关键组件之一。系统设计还对测试和维护活动以及软件系统生命周期中的进一步改进产生重大影响。软件设计应由软件系统的所有利益相关者以清晰易懂的方式反映需求的所有必要组成部分。为了区分系统元素，建议分离软件设计中的关注点。在这方面，用户任务的标识，即需要由用户执行的任务，目前未明确反映在系统设计文档中。我们在这项研究中的主要假设是，通过从需要由计算机系统本身执行的任务中清楚地识别出用户任务，可以显着提高软件质量。此外，我们提出的潜力有可能在软件设计上更好地反映用户需求和系统的主要目标，从而提高软件质量。这项研究的主要目的是在UML活动图（UML-AD）框架中为软件开发人员引入一种新颖的表示法，使设计人员能够识别用户任务并将其与系统任务分开定义。为此，提出了UML-AD的扩展，称为UML-ADE（扩展了UML-活动图）。此后，它在一个严肃的游戏案例中得以实现，对于该案例而言，用户任务的规范极为重要。最后，分析了其有效性，并通过实验与72名参与者进行了比较，并将其与UML-AD进行了比较。评价了参与者在两个现实生活中的严重游戏场景下的图上的缺陷检测性能。结果表明，使用UML-ADE的用户对它们的理解程度更高，这又表明设计更好，软件质量更高。结果鼓励研究人员开发专门用于任务设计的特定设计表示形式，以提高系统质量，并进一步评估这些设计对软件系统上述每个潜在好处的影响。结果表明，使用UML-ADE的用户对它们的理解程度更高，这又表明设计更好，软件质量更高。结果鼓励研究人员开发专门用于任务设计的特定设计表示形式，以提高系统质量，并进一步评估这些设计对软件系统上述每个潜在好处的影响。结果表明，使用UML-ADE的用户对它们的理解程度更高，这又表明设计更好，软件质量更高。结果鼓励研究人员开发专门用于任务设计的特定设计表示形式，以提高系统质量，并进一步评估这些设计对软件系统上述每个潜在好处的影响。