Legacy Systems
Legacy systems are like the old, generally reliable workhorses of the computing world, although some legacy systems may be more problematic than others. Legacy systems are the software applications or computer systems developed years ago that are still used today. Although legacy systems are found in manufacturing, they can also be found in non-manufacturing applications.
These systems have reached their end-of-life. End-of-life is a term used in computing when a device is no longer supported by the manufacturer. Even though they may no longer be supported, they may remain operational and continue to meet the organization’s needs, so the organization keeps using them.
Legacy systems, like a trusty old car, keep chugging along but lack updates and security. Generally, the cost to replace them is high. They are outdated but perform a critical role that is still in use, which is why companies do not want to replace them.
Legacy systems, despite their age, tend to be reliable. Although some legacy systems are like working with a house of cards, if you don’t try to make changes, they keep running. If they were too unreliable, the company would have replaced them.
The problem with legacy systems is that they are often costly to replace, both in terms of dollars and time. One other factor people may not consider is the cost of talent. With systems, especially when it comes to programming, it is very difficult to find anyone with the expertise and desire to work with the old technology. If your legacy system is coded with 10-year-old or more obsolete programming languages, good luck finding someone willing to maintain the code for you. New graduates will not want to learn an obsolete language, and anyone who used to code in it will probably charge you a premium price if they are willing to do it. You never know, with the improvements with AI it could offer solutions for managing legacy code down the line.
Replacing a legacy system in a company can be complex and expensive due to tight integration with other systems, hidden costs of migration, and fear of disruption and downtime. You can see why companies often don’t want to pay the price tag to replace the legacy system and keep using it. Don’t fix what’s not broken, right?
The problem with legacy systems is that they are outdated. This means that the manufacturer is not providing updates, which can cause security problems. Some argue that legacy systems can be more secure because they are older and better understood. However, due to no longer receiving updates, if an exploit is found, there will not be an update to fix it, making the legacy system vulnerable to certain attacks. To understand legacy systems, I will consider a real-world example.
Legacy Example
In a previous IT support role in a manufacturing facility, I supported automated machines similar to this one. These are automated machines designed for performing functions like cutting and drilling to make parts. These machines generally work for 10 to 15 years. The machines I used to support had been in use for around 20 years but were still working well.
Despite functioning adequately, the system in question is deemed legacy because the controller within the machine is outdated by current standards. Before delving deeper into this example, I will transition to another subject in this video as this clarifies why this is considered a legacy system.
Embedded Systems
Embedded systems are systems designed to perform a specific function. For example, sales terminals, smart TVs, voting machines, and industrial machinery. Embedded systems are often built into the product and difficult, if not impossible, to use for anything else. For example, there are many sales terminals that use small embedded PCs running Windows as the operating system, but it is not simple or even possible in many cases to remove the computer and use it for something else. The computer itself is often part of a PCB that contains other components, and in some cases, this includes the screen itself.
When working with embedded systems, remember they are designed for a specific purpose and often have only the minimal components required for that task. Since they are designed to only run that particular task, you can understand why it is hard to get them to do anything else. The benefit of these systems is that they are often more reliable than trying to use a general-purpose device to perform a specific function.
The following topics are in the official study guide; however, if you get a question on them, I doubt they will ask you for more than a very basic understanding of what they are.
Programmable Logic Controllers (PLCs)
When working with embedded systems in manufacturing, you will most likely come across Programmable Logic Controllers or PLCs. These are rugged industrial computers designed for manufacturing. They are the controllers that operate the machinery and are used for specific purposes. Since manufacturing machinery needs to be durable, so do the controllers that operate them.
Operational Technology (OT)
Embedded systems are often put on a separate network. I will go into the reasons for this in a moment. This network may be referred to as Operational Technology. In the real world, you probably won’t see this terminology used that much. Networks such as these are often called by other names describing the network function, like manufacturing network, machine network, or building management network. Sometimes these networks are called the IT of the non-carpeted areas. When working with manufacturing, it is not uncommon for these devices to be running on separate networks. Let’s have a look at why.
Legacy Example
I will now have another look at my previous example. The manufacturing machines I supported retrieved programs from an FTP server. The operator would choose the desired program directly from the FTP server. Once downloaded, the program controls the machine to produce the part.
When the machines were first purchased, they were added to the company’s network. Back then, security was not as big a concern as it is nowadays. As time went on, security became more of a concern. FTP transfers in text only, so it would be possible for someone on the network to copy the programs as they are transferred over the network.
Normally, to fix security problems, one common approach is to upgrade the machines. However, upgrading machines like these can cost hundreds of thousands of dollars. It is possible to upgrade just the controller in some cases, but this is still expensive. Thus, management may deem it too expensive to upgrade the machine just to improve security when the machine is still working well.
In other cases, the manufacturer may have gone out of business, or the model has gone end of life. In either of these cases, there may be no upgrade available. Although these types of machines are often supported for a long time, end of life is quite long when you are supporting machines that were designed to run for 10 years and are being used 20 years later. Don’t expect too much from the manufacturer.
Keep in mind that just because it is an embedded system does not make it a legacy system. What makes it a legacy system is when you can no longer upgrade it. In this case, the machines cannot be upgraded to a secure version of FTP. To add another concern, staff members have been approached by competitors wanting to purchase the programs. The competitors want the programs so they can replicate the parts on their own machines and sell them at a discount rate. Any staff member connected to the network could potentially copy the programs as they are transferred over the network.
In order to improve the security of legacy systems, one common method is to isolate the legacy system from other systems. If the legacy system is isolated, it reduces the security risk. Isolating the machines to a separate network, prevents staff members from accessing the network and copying the programs as they travel over the network.
It also prevents other systems on the network from causing problems. In this case, the network is only required to download the programs to the machine. If the machines are not able to download programs, the machines cannot make parts and thus production stops. When production stops, the company loses money.
You can see why isolating makes sense. This addresses the security concerns and helps prevent the network from being affected by any other problems on the company network.
Industrial Control System (ICS)
I will now go into some of the terminology used in industry. For the A+ exam, you only need a very basic understanding of these. Industrial Control Systems or ICS are computing systems designed to control and monitor industrial processes such as manufacturing, power generation, and water treatment, ensuring operational efficiency, reliability, and safety.
They are essentially the systems that control the machines. Think of it like this: if your heart was the machine, your brain would be ICS.
SCADA
The last system I will look at is SCADA. SCADA stands for Supervisory Control and Data Acquisition. This is a control system over a large geographical area. So, essentially, it is a system that controls all the other systems. For example, ICS would be used to control a single location, while SCADA would be used to control multiple locations.
In the CompTIA exam, if there is a question on the topics covered in this video, it is likely to focus on knowing what the terminology means and won’t go into much detail. The material appears to be provided to familiarize you with these key terms. I will now summarize the main points.
Summary
A legacy system is a system that is outdated but generally performs some sort of critical role that is still in use. These systems are often fairly reliable but can also be like a house of cards if used the wrong way. Generally speaking, if they were very unreliable, the company would have paid the money to get rid of them long ago.
Since a legacy system is outdated, security updates are no longer available, causing a security risk. Thus, a company will often isolate these systems. This helps keep them secure from attack and other systems interfering with them.
Embedded systems are systems that are designed to perform specific purposes. These include systems like sales terminals and control systems. In manufacturing, the embedded system may be a PLC. A PLC is a specific type of embedded system often used in machinery. PLCs are designed to be quite robust.
ICS and SCADA are systems designed to control other systems. ICS is used in a single location, while SCADA is used to control multiple locations over a large geographic area. I would not worry too much about remembering these systems for the exam. If you get a question, it will most likely just test that you have a basic understanding of what they are.
End Screen
Replacing a legacy system is sometimes like buying a new car. You know you should do it, but the cost is often enough to make you hold onto that old clunker for a few more years… even if it’s held together with duct tape and hope. Until the next video, thanks for watching.
References
“The Official CompTIA A+ Core Study Guide (Exam 220-1101)” pages 215 to 216
“Picture: Embed voting machine” https://commons.wikimedia.org/wiki/File:Accupoll-embedded-computer.jpg
“Picture: Sales terminal” https://commons.wikimedia.org/wiki/File:Quorion_concerto.jpg
“Picture: PLC” https://commons.wikimedia.org/wiki/File:Automate_industriel_WAGO_pour_un_syst%C3%A8me_de_monitoring_en_industrie_pharmaceutique.jpg
“Picture: PLC” https://commons.wikimedia.org/wiki/File:Siemens_sps_logo_8_12-24_RCE-03.jpg
“Picture: PLC” https://en.wikipedia.org/wiki/Programmable_logic_controller#/media/File:Siemens_Simatic_S7-416-3.jpg
“Picture: Compressor” https://commons.wikimedia.org/wiki/File:Elang_Compressor_Workshop.jpg
“Picture Electrical room” https://en.wikipedia.org/wiki/Electrical_room#/media/File:Electrical_switchgear.JPG
“Picture: Control room” https://en.wikipedia.org/wiki/Control_room#/media/File:Engine_control_room_on_oil_tanker.jpg
“Picture: Control room” https://commons.wikimedia.org/wiki/File:Kawerau_Geothermal_Power_Plant_Control_Room.jpg
“Picture: Control room” https://en.wikipedia.org/wiki/Industrial_control_system#/media/File:Leitstand_2.jpg
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