Maintainability is an important concept in software engineering and refers to the ability of a system to be maintained over time. It is a measure of how easy it is to make changes to a system without introducing new bugs or other problems. This includes making changes to the code, architecture, or design of the system. A maintainable system is one that is designed to be easy to modify and maintain, with minimal disruption to existing functionality. This includes having a well-defined structure, clear documentation, and good coding practices. Additionally, maintainability also includes having a good test suite to ensure that changes do not introduce new bugs or break existing functionality. Maintainability is an important factor in the success of any software system, as it allows for changes to be made quickly and efficiently, without sacrificing quality.