What are mission-critical applications?

The primary characteristic of a mission-critical application is the central role that it plays in enabling a business to operate. Mission-critical applications are often important to business continuity (an organization’s ability to perform during and after a crisis) and disaster recovery (a set of technologies and processes designed to restore essential functions after an unexpected event). When mission-critical applications fail or experience downtime, it can threaten a business’ core operations, reputation and sources of revenue. 

Mission-critical applications vary from industry to industry, and often a mission-critical application in one industry won’t be designated mission-critical in another. For example, an enterprise whose core business is emergency response would consider a communications network that allows ambulance drivers and dispatchers to talk mission-critical. However, another company in another industry might have a communications network that allows the drivers of their delivery vehicles to communicate, but wouldn’t necessarily designate this a mission-critical service.

By designating applications or workloads "mission-critical", IT infrastructure teams can help ensure that the appropriate resources are dedicated to their functions. For less important applications, IT teams will often use another label, such as "business critical" or "low priority". Low-priority applications are rarely included in business continuity plans (BCPs) or disaster recovery plans (DRPs), but business-critical applications are. 

A prolonged outage or downtime of a business-critical application needs to pose the threat of serious financial losses to a company or else IT teams should consider designating it a low-priority, or noncritical, application. Low-priority applications can perform below peak levels or sustain long periods of outage without damaging business operations or causing financial losses.

Once IT teams have successfully identified all their low-priority applications, they’re ready to separate the business-critical ones from the mission-critical ones. To determine whether an application should be considered mission-critical or business-critical, a simple set of criteria can be applied:

• Business-critical applications play an important role in an organization’s daily business operations, but their failure won’t prevent the enterprise from functioning. 
• Outages or downtime of business-critical applications impacts productivity but not as severely as failures of mission-critical applications. 
• When business-critical applications fail, there are alternatives users can rely upon, while mission-critical applications often have no alternatives. 

Most mission-critical applications have many users that rely on them to perform functions that are vital to a company’s success. Examples of activities that mission-critical applications enable include the delivery of goods and services, the safe storage of company data, the tracking of valuable assets and the processing of customer payments. A disruption to any of these processes would likely cause normal business operations to suffer.

Applications that directly impact an enterprises’ ability to maintain business continuity, securely store data or enable communication between employees and customers should be labeled mission critical. Here’s a closer look at each of these characteristics and how they apply in different scenarios. 

Business continuity: Failure of a mission-critical application must pose a serious risk to the business processes an enterprise has put in place. Common examples of how this might impact an organization include causing significant downtime, negatively impacting customer or employee safety, and interrupting productivity. 

Data storage: Many businesses, especially those that operate in industries where they must store sensitive customer data, label their data centers as mission critical. When a data center is breached, it can cause customer information to be compromised and result in financial fraud and reputational damage¹. 

User dependence: Most mission-critical applications are widely used by either employees, customers, or a combination of both. When a mission-critical application—such as a cloud messaging app such as Slack or iMessage—fails, normal business processes are disrupted and might not recover for days. 

Once an application has been identified as mission critical, IT teams must take appropriate steps to help ensure its availability and resiliency. Here are five well-established best practices enterprises rely upon when designing mission-critical applications.

Because of how important mission-critical applications are to the overall health of organizations, they must be highly available, meaning customers, employees and other users must have access to them close to 100% of the time. 

To help ensure continued availability, many enterprises build backups and redundancies into their BCPs and DRPs that apply to mission-critical applications. 

It’s important that mission-critical applications are able handle increased workloads during peak traffic times or companies will face potential downtime and the prospect of reputational damage. 

In 2022, when thousands of Taylor Swift fans tried to buy tickets to her new tour at the same time, the traffic caused the site ticketmaster.com to cease functioning, resulting in a public and embarrassing incident for the company².

Downtime is expensive, with costs averaging close to USD 9,000 per minute for large enterprises and reaching as high as USD 5,000,000 per hour in sensitive industries such as finance and healthcare³.

Enterprises that create strong disaster recovery plan for their mission-critical applications, including deploying the right solutions and backing up sensitive data, can significantly reduce their exposure to risk.

One way IT administrators can help ensure that mission-critical applications function under stressful conditions is to carefully evaluate their technical requirements and create multiple redundancies. A redundancy is a strategic duplicate of a critical component that might fail during an unexpected event. 

For example, data redundancy is the practice of backing up sensitive data in more than one location, so that if a disaster affects a single physical location, data stored elsewhere will remain secure. Another commonly deployed redundancy is "power-source redundancy" which involves establishing multiple, potential power sources for mission-critical systems that they can fall back on during a widespread outage.

Cloud migrations help IT administrators keep mission-critical applications running normally despite facing a broad range of complex threats. Private cloud and public cloud environments offer high availability (over 99% uptime for large cloud service providers (CSPs)) as well as high performance, security and automation. 

The maturation of the technology has allowed popular cloud providers such as Amazon Web Services (AWS), IBM and Microsoft Azure to increase the scope and complexity of their cloud offerings. Today, it’s common for enterprises to use the cloud to back up critical data, run virtual machine (VM) instances and even host mission-critical applications.

Applications that power an enterprise’s core business processes can range from simple, point-of-sale (POS) applications used in retail stores to sprawling enterprise resource planning (ERP) applications used to increase productivity. Here are some examples of the most widely used mission-critical applications that power today’s modern enterprises.  

These days, literally everyone has an app on their phone that lets them move money between bank accounts, make investments and even pay their bills. While banking used to be conducted in person at local branches, most of it is done online today. 

For the financial institutions that build and maintain these applications, their failure might result in customers losing access to their funds, cybersecurity fraud, widespread reputational damage and more. In a sensitive industry such as finance, even a couple of hours of downtime can generate negative headlines for large retail banks that depend on delivering the most cutting-edge financial technology (fintech) products to their customers in a safe, reliable manner.

Data storage centers are often considered mission-critical applications due to the importance of the information they house and the implications for a business if that information were to be deleted, stolen or otherwise damaged. 

Mission-critical data centers are typically built to be highly available and scalable, with multiple redundancies and backups in place, sometimes even in multiple, different physical locations to help ensure integrity. Still, widespread outages and cyberattacks have been known to damage data centers and the information they protect, leading to disruptions in normal business operations and reputational damage. 

Communication systems, such as mobile devices and cloud messaging applications, underpin most business processes in modern enterprises. The widespread shift to remote work during the pandemic has placed even more pressure on these systems to function. Failure of critical communication systems can result in loss of connectivity for a business’ entire workforce, leaving them unable to communicate with each other or their customers. 

Examples of this kind of incident are frequent, and every year, network outages at large cellular and software companies generate negative headlines in the press. Widespread outages such as the CrowdStrike incident earlier this year that impacted eight million Windows users, can leave employees and customers unable to perform their jobs or communicate for hours or even days⁴.

Modern transportation systems, such as trains, air travel and interstates, are mission-critical applications for the enterprises and communities that depend on them to function. 

For example, air traffic control systems, traffic grids and subways all present dire implications for the populations they serve if they face any periods of downtime. When these complex, highly interdependent systems fail, the results can be catastrophic, causing delays, accidents and expensive repairs. The IT administrators who build and monitor these systems build multiple redundancies and backup systems into their processes to prevent failures and help ensure quick and safe recovery periods following any interruptions.

Emergency services, such as the dispatching of ambulances and other resources vital to the safety of communities, are considered mission-critical applications and must have an availability rate that is close to 100%. Whether responding to a fire breaking out, an accident on the interstate or the report of a crime, fire, police and healthcare providers must be able to rely on the networks that allow them to communicate.

Still, emergency services can be impacted by common problems, including weather events, Internet and power outages and periods of unusually high demand for service. IT administrators must take these potential disruptions into account when designing the systems needed for emergency service mission-critical systems to function.