Software Maintainability: What it Means to Build Maintainable Software
Software is not static. If you build a valuable product that works perfectly but is difficult to modify and adapt to new requirements, it will not survive in today’s market. Maintainability is a long-term aspect that describes how easily software can evolve and change, which is especially important in today’s agile environment.
In this article you will learn:
- What is software maintenance
- Why software requires maintenance
- Software quality and maintenance
- Software maintenance types
- How to handle maintenance in agile projects
- Breaking out of the reactive maintenance model
What is Software Maintenance
Maintainability refers to the ease with which you can repair, improve and understand software code. Software maintenance is a phase in the software development cycle that starts after the customer has received the product.
Developers take care of maintainability by continuously adapting software to meet new customer requirements and address problems faced by customers. This includes fixing bugs, optimizing existing functionality and adjusting code to prevent future issues. The longevity of a product depends on a developer’s ability to keep up with maintenance requirements.
Software maintenance is the most expensive phase of development, typically consuming more than half of development budgets. It is important to plan maintenance into the development lifecycle so you can maintain software efficiently.
Why Does Software Require Maintenance?
There are a number of reasons to maintain software after you have delivered it to the customer:
- Bug fixing—involves searching for errors and correcting them to allow the software to run seamlessly
- Capability enhancement—enhancing the software to provide new features required by customers
- Replacement—replacing unwanted functionalities to improve adaptiveness and efficiency
- Security Issues—fixing security vulnerabilities found in your proprietary code or third-party code, especially open source components
Software Quality and Maintainability
Software quality and code quality can make a world of difference for software maintenance. Poor quality software is harder to maintain. Bad code requires a larger effort and costs more to adapt to new requirements. Software is more easily maintainable if it has high-quality code that is readable and well-documented, so keep good coding practices in mind while your software is still in development.
Software Maintenance Types
While performing maintenance, you can make four types of changes to your software:
- Corrective—detection and correction of faults. Users will often identify bugs and report them. It is important to make corrective changes regularly.
- Adaptive—changes to your software that keep it compatible with the changing software environments such as hardware and operating systems. You need to make these changes regularly to keep your product up to date.
- Perfective—improving system functionalities. This includes both small changes to features like UI as well as more significant improvements to the code that boost performance. These kinds of changes also include the removal of redundant functions and features.
- Preventive—tackling potential issues. By making preventive changes you protect your software from failures as well as avoid costs that fixing them would require.
How to Handle Maintenance in Agile Projects
Maintaining software in an agile project is challenging. It requires maintaining legacy software and fixing its bugs alongside the development of new products. Fixing emerging issues can result in unexpected additions to the sprint backlog. This makes it harder to accurately plan and manage sprints. Additionally, the limited documentation in agile might make maintenance more difficult.
Breaking Out of the Reactive Software Maintenance Model
Both developers and their managers would like for more dev resources to be spent on new functionality that benefits users and increases revenue. In reality, however, a growing portion of developer time is taken up by the second part—maintenance and bug fixing.
For new software projects that haven’t yet accumulated much technical debt, it is still possible to invest most of your time on new feature development. The more a software product grows, the more technical debt accumulates until maintenance time can become the dominant portion of an agile team’s workload.
The key to solving the problem is intelligent prioritization. If agile teams had exact data about which parts of the product are error-prone and likely to impact the customer, they could focus maintenance effort on these areas, and save valuable time for development of new features.
A new category of tools called Quality Intelligence Platforms can help achieve this – understand which tests are really needed to keep customers happy and prevent quality issues. They do it by:
- Monitoring tests and test frameworks at all levels—including unit, functional, integration, end-to-end, and manual tests
- Tracking code changes—to identify which major changes in the current release are sufficiently tested—and so do not represent a quality risk.
- Tracking code usage in production—to identify which features are used by end users and what is essentially “dead code”, which does not need to be tested.
- Visualizing the data—to provide visibility into which tests exist, which do not, which parts of the software are at risk of quality issues
SeaLights is a quality intelligence platform which provides this missing visibility—exactly what you need to focus maintenance work and reduce developer time wasted on reactive maintenance.
Read our white paper to learn how to move from endless reactive software maintenance to a proactive model which anticipates quality issues and focuses on those that matter most: Reactive Software Maintenance: The Silent Killer of Developer Productivity