Do Energy-oriented Changes Hinder Maintainability?

TL;DR

This study investigates how energy efficiency improvements in Android apps impact maintainability, revealing that such changes often decrease maintainability but providing insights for better development practices.

Contribution

It offers an empirical analysis of energy-oriented commits' effects on maintainability and provides practical guidelines for developers and researchers.

Findings

Energy efficiency improvements often decrease maintainability.

Code changes for Power Save Mode and Wakelock increase tend to reduce maintainability.

Manual analysis highlights specific maintainability issues caused by energy-oriented modifications.

Abstract

Energy efficiency is a crucial quality requirement for mobile applications. However, improving energy efficiency is far from trivial as developers lack the knowledge and tools to aid in this activity. In this paper we study the impact of changes to improve energy efficiency on the maintainability of Android applications. Using a dataset containing 539 energy efficiency-oriented commits, we measure maintainability -- as computed by the Software Improvement Group's web-based source code analysis service Better Code Hub (BCH) -- before and after energy efficiency-related code changes. Results show that in general improving energy efficiency comes with a significant decrease in maintainability. This is particularly evident in code changes to accommodate the Power Save Mode and Wakelock Addition energy patterns. In addition, we perform manual analysis to assess how real examples of energy-oriented changes affect maintainability. Our results help mobile app developers to 1) avoid common maintainability issues when improving the energy efficiency of their apps; and 2) adopt development processes to build maintainable and energy-efficient code. We also support researchers by identifying challenges in mobile app development that still need to be addressed.