Reliability Vs. Availability: Definitions And Comparison

Indeed Editorial Team

Updated 21 September 2022

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

Measuring the ability of a business to handle disruptions can be an excellent step towards achieving your employer's goals. Two measures of this process are reliability and availability. Knowing about what availability and reliability are, how they are different and how to measure them can allow you to participate in the growth of a business. In this article, we explore the comparison of reliability vs. availability and share the steps you can take to increase both.

Reliability Vs. Availability

Understanding how reliability vs. availability compare can help you find ways to increase efficiency in the workplace. This is because both terms relate closely to the daily operation of businesses. To understand how these concepts affect operations, consider the following comparisons:


Reliability is a way to measure the ability of equipment in the business to fulfil its purpose. This means that professionals can monitor the use of a tool or piece of equipment to determine if it is helpful to the business and can help employees in daily operations. For example, in a textiles warehouse, professionals may determine a sewing machine's reliability by determining how many garments an employee can complete before needing to reload the spool of thread that the machine uses. They may also examine how often the tool malfunctions or needs repairs to factor into this measurement.

Availability is the chance that a system is ready to use. You want high availability during the operating hours of a business. That way, you can accomplish tasks with that equipment quickly. For example, if a restaurant's employees take 15 minutes to sharpen knives every shift, this means that the knives are unusable for at least 15 minutes daily, decreasing its availability. Professionals measure availability with the following formula:

Availability = Mean time between failures/mean time between failures + mean time to repair

Related: What Does An Operations Manager Do? (With Skills And Duties)


Some professionals may confuse availability and reliability because of their similar definitions. These concepts have a close relation to each other, and share the following similarities:

  • Productivity: When the company for which you work increases both the availability and reliability of its equipment, you may experience an increase in productivity.

  • Machine maintenance: Both terms relate to machine maintenance and performing proper and preventative repairs for equipment can increase the value of each of these measurements.

  • Profit: Because increasing the availability and reliability of a tool can increase productivity, it also often leads to an increase in company profits.

  • Efficiency: Increasing these measurements for a company can help ensure that employees can complete their tasks efficiently.

Related: What Does A Machine Operator Do? (Duties And Salary)


Though these concepts share many similarities, each term has nuances that separate them by definition and use. Here are some of the differences between these terms:

  • Exclusivity: The two measures are not reliant on each other, so an available machine is not necessarily a reliable one.

  • Time: While availability focuses on the loss of time, reliability focuses on the impact of that lost time.

  • Dependence: As reliability focuses on the impact of the time companies lose in the production process, reliability depends on availability, but this is not a mutual relationship.

Related: Automation Testing (With Definition, Types And Benefits)

How To Increase Reliability

Here is a list of steps you can take to increase the reliability of the machines the company for which you work uses:

1. Create training programmes

You can prevent some system and equipment failures by training the team in the proper use and maintenance of tools. For example, training kitchen staff on how to use and maintain sharp kitchen knives can keep the knives from breaking down as quickly or causing disruption when completing orders. Some examples of training include how to use and operate machinery and how to maintain equipment. This training may also help improve employees' skill levels regarding the use of the equipment, which can increase the productivity of the workplace.

Related: 9 Different Methods Of Training For Employees With Benefits

2. Focus on continuous improvement

Continuous improvement is a process in which professionals dedicate themselves to consistently reaching goals and improving the quality of their work and other factors that can affect production. After fixing one problem or implementing a new task, move on to the next one to make it more efficient for the business. As you become more aware of each process, you can take preventative actions to make sure equipment stays in good working order. Recognising areas of improvement and constantly looking for new ways to increase reliability can also help you gain new equipment to meet the needs of the business.

Related: 5 Continuous Improvement Examples (And How To Incorporate)

3. Monitor the operation of the equipment

You can increase reliability by collecting data about each piece of equipment that the company has. Knowing the condition that the equipment is in and the most common ways that equipment fails can help you plan preventative maintenance, which can decrease the time that equipment is down for repairs. Collecting this data can help ensure you have enough information to determine each measurement, which can prepare you to increase the reliability of the company's equipment.

Related: A Quick Guide To Operations Management Responsibilities

4. Perform a failure mode and effects analysis (FMEA)

After you collect data about the most common ways your employer's equipment fails, you can perform failure mode and effects analysis to prevent those failures. The four most common categories that failures fall into are:

  • Safety

  • Production

  • Equipment costs

  • Environment

Using these four categories, you can plan preventative maintenance that can keep your equipment from failing. This can help decrease the need for emergency maintenance and unexpected equipment malfunctions, which can help increase the tool's reliability. It also helps ensure that you and the team do not lose any production time during business hours.

Related: 10 Quality Tools To Use (With Definition, Benefits And Tips)

5. Optimise your inventory

You can optimise the company's inventory for maintenance tasks by predicting the needs of the machines and tools. Optimising the company's maintenance inventory often involves by tools and supplies to perform common maintenance tasks. This can help decrease the time in which employees wait to use a tool due to a malfunction. This is because with the supplies needed to repair the equipment readily available, maintenance professionals can perform their tasks more efficiently.

How To Increase Availability

If you are interested in increasing the availability of the tools and equipment you and your colleagues use, consider following these steps:

1. Measure the machine's current availability

By calculating the current availability of the equipment, you can determine how often its availability matches the business' needs. If the equipment is almost always available, then it is operating at almost top efficiency and can help you keep company costs down. If it is very low, as in there is a 50% or less chance the equipment is available, you can take steps to start raising that equipment's availability.

2. Identify the achievable availability

Your achievable availability is what you achieve when the business is functioning optimally. Its value can help you determine where the inefficiencies are and where it may be possible to rework the process. It is possible that 99% availability isn't workable for the business. If that is the case, then you can focus on raising the availability of the equipment in small increments and slowly adjust the budget as it becomes available.

Related: How To Set And Achieve Long-Term Goals (With Examples)

3. Stay up-to-date on operational practices

Some limitations to availability come from operational practices. As you increase the availability of your equipment, you can update the operational practices and provide training to keep your equipment in good working condition. Just like with reliability, keeping your team prepared with the knowledge to use the equipment effectively can increase availability.

Related: 15 Types Of Operations Metrics And Their Use In Business

4. Perform preventative maintenance measures

By implementing effective preventative maintenance, you can increase the chance that employees can use the equipment during operational hours. Scheduling time outside of business hours to go through the equipment can save more time during the operational day and keep your mean time to repair much lower.

Using predictive sensors and other technology as it becomes available to the business for which you work can help you streamline preventative maintenance. It can help you schedule maintenance only when it is necessary and not at other times, potentially saving the company valuable time and money. It is important to note that having a good preventative maintenance plan can help you when implementing a new predictive maintenance tool.

Related: 7 Important Skills For A Heavy Equipment Operator To Have

5. Improve company scheduling methods

Using good scheduling practices can help you decrease logistical delays. When considering the availability of equipment, keep in mind these aspects:

  • Locations of equipment, storage and the people who work for your business

  • Transport time of repair materials

  • Communicating with operational teams to schedule downtime for equipment repair that doesn't conflict with the availability of the equipment

  • Scheduling tasks based on what is most important

  • Considering the training required for maintenance and scheduling tasks

Explore more articles