A literate process for the certification of scientific and engineering software

我们的主要目标是开发可认证的科学和工程软件。当前过程的一个问题是，软件工件之间存在相当多的重复，以及这些工件之间明确缺乏可跟踪性。我们相信，我们可以解决这两个问题，通过适应背后的思想识字编程（LP），在程序编写的第一个目标是理解人类读者，而不是被人为地限制由传统的计算机代码所需的顺序和格式。在经典的LP，从识字的源文件中提取两个项目：用户可读的文档和计算机可读的源代码。我们提出的文字处理过程将扩展这一思想，使“源”文件可以以多种方式处理，不仅提取代码及其解释，而且提取需求规范，应用程序接口（API），测试用例，测试报告和构建说明。这将使我们能够共享所有这些软件工件之间大量的共同信息，从而减少重复。为了开发、激励和记录识字过程，我们将使用一个常微分方程（ODE）求解器家族的代码生成案例研究。在族方法中，代码的生成考虑到了族中的共性，但根据其变异性来区分每个成员。代码生成方法促进了认证组件的重用，从而实现快速认证。ODE求解器的家庭将被放在核安全分析的背景下。特别是，将开发一个例子，解决了系统的常微分方程的一部分，在核反应堆中的燃料棒的热分析。

Our principal objective is to develop certifiable scientific and engineering software. One problem with current processes is that there is considerable duplication between software artifacts, as well as a definite lack of traceability between these artifacts. We believe that we can solve both of these problems by adapting the ideas behind Literate Programming (LP), in which programs are written first with the goal of being understandable to human readers, rather than being artificially constrained by the ordering and formatting required by conventional computer code.In classical LP, from literate source files two items are extracted: the user readable documentation and the computer readable source code. Our proposed literate process will extend this idea so that "source" files can be processed in multiple ways to extract not just the code and its explanation, but also the requirements specification, the Application Program Interface (API), the test cases, the test report and the build instructions. This will allow us to share the considerable amount of information in common between all these software artifacts, thus decreasing duplication. At the same time traceability is increased, since this shared information will be extracted into the correct artifacts.To develop, motivate and document the literate process we will use a case study of code generation for a family of ordinary differential equation (ODE) solvers. In the family approach code is generated taking into account the commonalities in the family, but distinguishing each member based on its variabilities. The code generation approach facilitates reuse of certified components, leading to quick certification. The family of ODE solvers will be put in the context of nuclear safety analysis. In particular, an example will be developed that solves a system of ODEs as part of the thermal analysis of fuel pins in a nuclear reactor.