Ph.D. student Chin Khor and Dr. Robyn Lutz recently received the 2023 award for Best Industrial Innovation Paper at the 31st IEEE International Requirements Engineering Conference. Khor presented the paper, “Requirements Analysis of Variability Constraints in a Configurable Flight Software System,” at the conference in Hannover, Germany.
Variability constraints are an essential part of the requirements for a configurable system. The constraints specified in the requirements define which combinations of configuration options will work and which are not allowed. The paper reports on a solution to a challenge faced by new developers wanting to use a recently open-sourced NASA flight software framework. The challenge is that the specifications of variability-related requirements and constraints are scattered across multiple documents. This scattering can contribute to misunderstandings of the side-effects of design choices, increased effort for developers, and bugs during operations.
The solution proposed by Khor and Lutz introduces a new software variability model, similar to a product-line feature model, into the flight software framework. The paper describes the structured technique by which the model is developed, demonstrates its use, and evaluates it on a key service module of the flight software. Results show that this lightweight modeling technique, engineered to be practical for use by developers, helped find missing and inconsistent variability-related requirements and constraints. More generally, the work suggests that a variability modeling technique such as this can be an efficient way for developers to centralize specification and improve the analysis of scattered variability-related requirements and constraints in other configurable systems.