In a software-centric world, organizations are seeking ways to fulfill the continuous demand to deliver new and improved IT solutions. These demands have spurred companies to adopt more efficient software development practices. Software solutions have become bigger and more complex, and they require high quality. Serving customers without compromising delivery quality is critical for companies. It’s equally important to improve the reliability of software solutions without hindering the speed of innovation. Quality and reliability are complementary pieces of a puzzle that fit together well. In the following sections, you will see how quality vs reliability differ, yet help enhance the software development and delivery process.

What Is Quality?

Every company aims to build and deliver best-in-class software solutions that resonate with customer requirements. Whenever a software solution is ready to be shipped, the ultimate expectation criteria is quality. Software quality tells you how well a service performs its intended function. In other words, it’s the conformance measure to the stated or implied product specification. Furthermore, you must define the right quality controls at each stage of the application delivery lifecycle to make sure that the product meets quality goals. Eventually, it’ll decrease bugs and errors while preventing costly rework.

Continuous monitoring can help detect application performance issues, identify the root cause of these issues, and implement a solution before it leads to unplanned application downtime and lost revenue. This helps streamline the deployment process and ensure product quality before moving into production. When conducted at early stages, bug fixes make sure that the delivery of high-quality, reliable, and competitive software products remains on time. In a survey conducted by the Ponemon Institute in 2017, it was found that if vulnerabilities are detected in the early development process, they could cost $80 on average. However, the same vulnerabilities, if detected after they’ve moved into production, could cost $7,600 to fix. 

Continuous Verification offered by Harness lets you rapidly detect regressions or anomalies, as well as roll back failed deployments. Harness aggregates data from multiple APMs and logs providers. This helps isolate issues before final deployment, and it lets you roll back in case of any anomalies. This can ultimately save you time, revenue loss, and reputational damage. 

Quality vs Reliability: Rolling Back

What Is Reliability?

In simple terms, reliability is how well a product or service maintains its original quality over time and in various conditions. This is the fundamental feature of any product, and it’s measured during or after a customer uses the product. For example, consider a scenario where a service has 90% reliability for a month. This means that, under normal usage conditions during this month, there will be a 90% chance that the service won’t experience any critical failures. This service attribute specifies how likely it’ll function without a failure for a given timeframe under predefined conditions.

In other words, reliability simply reflects how well a service behaves, and it’s a means of measuring whether a service meets the expected behavior over time. 

Consider another scenario where a customer demands that a service must process every transaction within a one second timeframe, and it fulfills this requirement 99% of the time while also maintaining a 99% availability level. You can consider that service to be a reliable one. Contrary to this, if the service responds to all of the requests but suffers from high error rates, then that service would be highly available but unreliable.

Harness Service Reliability Management (Harness SRM) helps engineering and DevOps teams create reliability guardrails within CI/CD pipelines to balance feature velocity and bug fixes along with the stability and reliability needs of a production environment. Harness SRM lets users define, measure, and track SLIs, SLOs, and Error Budgets. Moreover, running the right checks at the right stages of a pipeline (shift-left reliability) helps you continuously improve reliability and deliver software faster with the confidence that it’ll be reliable. You can find a list of SRM’s key capabilities here


Hopefully you now have a better understanding of quality vs reliability. If you’re interested in learning more about Harness SRM, please read our documentation. Please request a demo if you’re interested in a more hands-on look into SRM.