# Are Architectural Smells Independent from Code Smells? An Empirical Study

## TL;DR

This study investigates whether architectural smells are independent of code smells, finding that they are only weakly correlated and should be treated as separate issues in software quality management.

## Contribution

The paper provides empirical evidence that architectural smells are largely independent from code smells, challenging assumptions of their derivability from code smells.

## Key findings

- Architectural smells are rarely correlated with code smells.
- Architectural smells cannot be reliably derived from code smells.
- Architectural smells require separate attention in software maintenance.

## Abstract

Background. Architectural smells and code smells are symptoms of bad code or design that can cause different quality problems, such as faults, technical debt, or difficulties with maintenance and evolution. Some studies show that code smells and architectural smells often appear together in the same file. The correlation between code smells and architectural smells, however, is not clear yet; some studies on a limited set of projects have claimed that architectural smells can be derived from code smells, while other studies claim the opposite. Objective. The goal of this work is to understand whether architectural smells are independent from code smells or can be derived from a code smell or from one category of them. Method. We conducted a case study analyzing the correlations among 19 code smells, six categories of code smells, and four architectural smells. Results. The results show that architectural smells are correlated with code smells only in a very low number of occurrences and therefore cannot be derived from code smells. Conclusion. Architectural smells are independent from code smells, and therefore deserve special attention by researchers, who should investigate their actual harmfulness, and practitioners, who should consider whether and when to remove them.