Governing the Commons: Code Ownership and Code-Clones in Large-Scale Software Development

TL;DR

This paper investigates how different teams in large-scale software development introduce code clones and technical debt, using a statistical model to visualize team behaviors and provide insights for managing collective code ownership.

Contribution

It introduces a Multi-Level Generalized Linear Model to analyze and visualize team-specific behaviors in code clone introduction across components, aiding understanding of collective ownership impacts.

Findings

Teams behave differently across components.

Model-based visualizations are useful for understanding team behavior.

Practitioners find the visualizations insightful for managing code ownership.

Abstract

Context: In software development organizations employing weak or collective ownership, different teams are allowed and expected to autonomously perform changes in various components. This creates diversity both in the knowledge of, and in the responsibility for, individual components. Objective: Our objective is to understand how and why different teams introduce technical debt in the form of code clones as they change different components. Method: We collected data about change size and clone introductions made by ten teams in eight components which was part of a large industrial software system. We then designed a Multi-Level Generalized Linear Model (MLGLM), to illustrate the teams' differing behavior. Finally, we discussed the results with three development teams, plus line manager and the architect team, evaluating whether the model inferences aligned with what they expected. Responses were recorded and thematically coded. Results: The results show that teams do behave differently in different components, and the feedback from the teams indicates that this method of illustrating team behavior can be useful as a complement to traditional summary statistics of ownership. Conclusions: We find that our model-based approach produces useful visualizations of team introductions of code clones as they change different components. Practitioners stated that the visualizations gave them insights that were useful, and by comparing with an average team, inter-team comparisons can be avoided. Thus, this has the potential to be a useful feedback tool for teams in software development organizations that employ weak or collective ownership.