reliability engineering

What is reliability engineering?

Reliability engineering focuses on the ability of systems to perform as it is intended to and function without failure in a specified environment, for the required time duration.

Reliability engineering can be applied across the entire lifecycle of software development. It is designed to increase the dependability of a product by detecting potential reliability issues early in the software development cycle, and correcting causes of failure that do occur.

Catching issues as early as possible helps organizations to create more reliable products and help teams to increase the mean time between failures (MTBF).

Ultimately, this will help organizations to produce better products and to improve their reputation.

Why do you need reliability engineers?

reliability engineering

Reliability engineers are required to ensure that the reliability of a product or service is maintained by identifying and managing reliability risks that could have adverse effects on business operations.

Some examples of tasks performed by reliability engineers include:

  • Working with teams to design and test systems
  • Performing root cause analysis to find out why systems are failing
  • Ensuring actions are addressing the right failures

This can help organizations to increase their throughput, enhance their brand image, and by extension increase their profits.

Objectives of a reliability engineer

The main objective of a reliability engineer is to identify an organization’s critical assets and manage asset reliability risks that may adversely affect business operations.

The role of a ‘reliability engineer’ itself is broad, and it can be divided into three smaller roles as outlined below:

Loss elimination

This involves tracking downtime losses and costs, then finding ways to reduce or eliminate these losses. This is typically done through root cause analysis, which focuses on discovering and addressing the root cause of the problems. The purpose is not to eliminate every single loss by solving every single problem. Rather, the goal is to solve the vital few problems that are causing most of the issues within the system.

Risk management

This involves identifying and managing risks that could have a detrimental effect on operations. Risks can arise at any stage, which means that risk management approaches should be considered and applied throughout the project.

Reliability engineering principles

reliability engineering

Google has outlined several principles that are designed to outline how SRE teams work.

They describe the patterns, behaviors, and causes for concern that may influence SRE operations within an organization.

Below is a brief overview of these principles:

Manage risk

Improving service reliability is largely about embracing risk and managing it effectively.

SREs are required to consistently assess the level of risk, manage risk, and use error budgets effectively.

Managing risk can be costly, so it’s important to carefully consider the profile of a service when making a decision about how much risk an organization is willing to take.

Create Service Level Objectives (SLOs)

SLOs are designed to help organizations to define and deliver a certain level of service to users. They provide a key way for organizations to measure the performance of a service provider and avoid misunderstandings between parties.

Choosing appropriate SLOs helps teams to understand when a service is performing well, and also helps them to get back on track when things go wrong.

Eliminate Toil

‘Toil’ is defined as repetitive, mundane work that scales as the organization grows and ultimately provides little to no enduring value. It is typically repetitive, manual, and automatable. It can include tasks such as team meetings, setting goals, evaluating goals, and completing paperwork. Eliminating toil is important for teams to improve productivity.

Continuously Monitor

Consistent monitoring is vital to ensure that a system is functioning how it should, and therefore that it is reliable. It involves collecting real-time data about a system and processing, aggregating, and displaying it.

Examples of system data that SRE teams may collect include query counts, error counts, and processing times.


Considering how to simplify every task encourages teams to clarify what it is that they want to accomplish, and makes them think more deeply about how we can achieve this.

Rejecting a particular feature is not about restricting innovation – it’s about getting rid of distractions to ensure as much innovation as possible.

Reliability engineering tools

Some of the key tools used by reliability engineers include:

  • PagerDuty – an incident response tool that integrates with a variety of DevOps tools to send notifications and calls to the mobile devices and smartwatches of on-call engineers.
  • DataDog – a cloud monitoring solution that aggregates metrics and events throughout the system to allow teams to see what is going on inside their app.
  • Reliably – allows teams to create objectives, monitor a service’s health by aggregating a reliability score, and helps keep teams updated about how close they are to objectives.