Prototyping is an effective and efficient way of requirements validation to avoid introducing errors in the early stage of software development. However, manually developing a prototype of a software system requires additional efforts, which would increase the overall cost of software development. In this article, we present an approach with a developed tool RM2PT to automated prototype generation from formal requirements models for requirements validation. A requirements model consists of a use case diagram, a conceptual class diagram, use case definitions specified by system sequence diagrams, and the contracts of their system operations. A system operation contract is formally specified by a pair of pre and postconditions in object constraint language. We propose a method with a set of transformation rules to decompose a contract into executable parts and nonexecutable parts. An executable part can be automatically transformed into a sequence of primitive operations by applying their corresponding rules, and a nonexecutable part is not transformable with the rules. The tool RM2PT provides a mechanism for developers to develop a piece of program for each nonexecutable part manually, which can be plugged into the generated prototype source code automatically. We have conducted four case studies with over 50 use cases. The experimental result shows that the 93.65% system operations are executable, and only 6.35% are nonexecutable, which can be implemented by developers manually or invoking the third-party application programming interface (APIs). Overall, the result is satisfactory. Each 1 s generated prototype of four case studies requires approximate one day's manual implementation by a skilled programmer. The proposed approach with the developed computer-aided software engineering tool can be applied to the software industry for requirements engineering.

中文翻译：

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从正式需求模型自动生成原型

原型设计是一种有效且高效的需求验证方式，可避免在软件开发的早期阶段引入错误。然而，手动开发软件系统的原型需要额外的努力，这会增加软件开发的总体成本。在本文中，我们介绍了一种使用开发工具 RM2PT 来从正式需求模型自动生成原型以进行需求验证的方法。需求模型由用例图、概念类图、系统序列图指定的用例定义及其系统操作的契约组成。系统操作契约由对象约束语言中的一对前置和后置条件正式指定。我们提出了一种具有一组转换规则的方法，将合约分解为可执行部分和不可执行部分。可执行部分可以通过应用相应的规则自动转换为原始操作序列，而不可执行部分则不能通过规则转换。RM2PT工具为开发者提供了一种机制，可以为每个不可执行的部分手动开发一段程序，可以自动插入到生成的原型源代码中。我们已经进行了四个案例研究，涉及 50 多个用例。实验结果表明，93.65%的系统操作是可执行的，只有6.35%是不可执行的，可以由开发者手动或调用第三方应用程序接口（API）来实现。总的来说，结果是令人满意的。四个案例研究的每个 1 s 生成的原型需要熟练的程序员大约一天的手动实施。所提出的方法与开发的计算机辅助软件工程工具可以应用于软件行业的需求工程。