Have you ever stopped to wonder about how it is that the world is able to keep on ticking? While it’s not all smooth-sailing, when you really think deeply about it, humanity has collectively done an impressive job of building infrastructure to support the lives of, well, billions of people. Our ability to construct systems is, after all, what prevents unnecessary accidents, ensures precious information is secure, and allows high-speed, large-scale societies to function — global energy crises aside.
All of this, however, depends on the role of safety measures in place, which minimise the risk of what happens when important systems fail. The appliance or technology that deals with hazardous contingencies in this way is one example of a “mission-critical” system, which is the focus of this article.
Here we will unpack the function of mission-critical systems through four prime case studies.
What does mission-critical mean?
Putting it briefly, a mission-critical system is physical hardware, computer or electronic systems that are vital to the success of an operation. This means that, when a mission-critical system fails, it can quickly do lasting damage.
Generally speaking, interruptions to these types of appliances or systems do any of the following:
- Inhibit safe meeting of business objectives
- Negatively impact quality levels
- Breach an organisation’s environmental standards and regulations
Four types of mission-critical systems
Hospitals are, as you might expect, filled with systems considered critical for patient care. The failure of these appliances poses the risk of serious injury or death, making an in-built failsafe and other safety designs absolutely essential. One such example of a critical system is a patient monitoring device in intensive care units, which make use of mobile, compact x-ray machines that precisely control the focus and dosage of x-rays. Others include CT scanners, dialysis systems and sterilisers.
Taking the patient monitoring device as our example, this is connected to a central system that helps to ensure that any failures are unlikely to result in harm. However, they also require a combination of power supply types, relying on high-voltage and high isolation DC/DC converters, and compact AC/DC power supplies.
The former provides essential isolation barriers that, as XP Power explains, “ensure that the applied part is isolated from the ground and meets the patient leakage current limits during normal and single fault conditions”. In other words, the system needs isolated components to keep the electrical current contained so that it doesn’t endanger the patient.
The latter, on the other hand, makes sure that monitoring devices can handle the use of pulse loads. These are instant bursts of energy that are accumulated over a relatively long period of time, and released automatically by a machine. If the machines cannot handle this level of current, it can otherwise damage the circuit, burn the resistors and potentially any surrounding objects.
For aeroplanes and other aircrafts to operate safely, they require a navigation system. These are considered mission-critical as they are fundamental to the functioning of the vessel. The method or system a pilot will use varies between types of flights and the type of navigation systems used. Commonly, passenger jets use a combination of GPS and other tools, including what are termed Inertial Navigation Systems (INS). This measures the speed and movement changes of the craft to determine its location, with a process called dead reckoning using visual checkpoints alongside the INS.
The in-flight computer system also helps pilots calculate distance and time of the designated checkpoint they set. The final part of the navigation system are radio aids used for specific parts of the flight. According to Flight Deck Friend: “the more radio signals that can be detected, the more accurate the estimated position is”.
Nuclear reactor safety system
A nuclear reactor contains the chain reaction used to generate electricity or other forms of power such as isotopes, which are radioactive energy with an altered atomic mass. These reactors have caused a great deal of public safety concern due to the heavy risk of nuclear power. The most obvious example is the Chernobyl disaster in 1986, which resulted in the deaths of around 60 people, and is speculated to have led to the early demise of up to 16,000 overall. Safety systems for nuclear reactors are therefore a prime example of how to insure against mission-critical failures such as these.
To manage the operation of these systems, the chain reaction inside the nuclear reactor is manipulated, usually through the use of water and the control rods that can impact the chemical process. The “shutdown system”, as it is called, automatically sinks the rods to halt the chain reaction, and liquid is also there to be immediately injected when problems are encountered.
Transport layer security (TLS)
Transport layer security, or TLS, is a cryptographic protocol to ensure secure communications in a computer network, with cryptography referring to the writing or solving of code. TLS is mission-critical in that it safeguards against compromised security of information in confidential communications. You’ll find it in emails, instant messengers and most recognisably, HTTPS. As Comparitech explains: “as long as an appropriate algorithm is used, attackers will not be able to access the actual data, even if they intercept it.”
The main function of TLS is to cryptographically set up privacy barriers through the use of certificates, between two or more communicating computer applications. It operates in the relevant application itself, such as an email server, and consists of two layers: the record and the handshake protocols. The former is used to secure data, and the latter starts the encrypted communication process between two or more participants. However, as Internet Society clarifies: “TLS does not secure data on end systems. It simply ensures the secure delivery of data over the Internet, avoiding possible eavesdropping and/or alteration of the content”.