Just Formal Enough? Automated Analysis of EARS Requirements

Levi Lúcio, Salman Rahman, Chih-Hong Cheng and Alistair Mavin

NASA Formal Methods - 9th International Symposium, NFM 2017, Moffett Field, CA, USA, May 16-18, 2017, Proceedings, pp. 427–434

May 2017 · doi: 10.1007/978-3-319-57288-8_31


EARS is a technique used by Rolls-Royce and many other organizations around the world to capture requirements in natural language in a precise manner. In this paper we describe the EARS-CTRL tool for writing and analyzing EARS requirements for controllers. We provide two levels of analysis of requirements written in EARS-CTRL: firstly our editor uses projectional editing as well as typing (based on a glossary of controller terms) to ensure as far as possible well-formedness by construction of the requirements; secondly we have used a controller synthesis tool to check whether a set of EARS-CTRL requirements is realizable as an actual controller. In the positive case, the tool synthesizes and displays the controller as a synchronous dataflow diagram. This information can be used to examine the specified behavior and to iteratively correct, improve or complete a set of EARS-CTRL requirements.

subject terms: Natural Language, Linear Temporal Logic, Requirement Engineer, Controller Synthesis, Model-based Systems Engineering, MbSE

url: https://doi.org/10.1007/978-3-319-57288-8\_31