Towards A Catalogue of Requirement Patterns for Space Robotic Missions

TL;DR

This paper explores the applicability of reusable requirement specification patterns for space robotic missions, formalising mission requirements and extending the pattern catalog with new patterns validated by expert evaluation.

Contribution

It formalises space mission requirements using existing patterns, introduces five new patterns, and evaluates their effectiveness through expert feedback.

Findings

Existing patterns are applicable to space missions

Five new requirement patterns were developed

Expert evaluation highlighted benefits and limitations

Abstract

In the development of safety and mission-critical systems, including autonomous space robotic missions, complex behaviour is captured during the requirements elicitation phase. Requirements are typically expressed using natural language which is ambiguous and not amenable to formal verification methods that can provide robust guarantees of system behaviour. To support the definition of formal requirements, specification patterns provide reusable, logic-based templates. A suite of robotic specification patterns, along with their formalisation in NASA's Formal Requirements Elicitation Tool (FRET) already exists. These pre-existing requirement patterns are domain agnostic and, in this paper we explore their applicability for space missions. To achieve this we carried out a literature review of existing space missions and formalised their requirements using FRET, contributing a corpus of space mission requirements. We categorised these requirements using pre-existing specification patterns which demonstrated their applicability in space missions. However, not all of the requirements that we formalised corresponded to an existing pattern so we have contributed 5 new requirement specification patterns as well as several variants of the existing and new patterns. We also conducted an expert evaluation of the new patterns, highlighting their benefits and limitations.