SCADA vs. Industrial IoT (IIoT), which should you choose?

A timeless question that arises whenever you’re looking for a system to help you automate and control critical processes in the industrial sector.

While SCADA (Supervisory Control and Data Acquisition) looks like the way to go because of its reliability and track record, industrial IoT (Internet of Things) brings innovation to the table. The good news is both systems offer unique advantages.

The right choice depends on your industry’s needs. But for that, you need to understand what each of these systems bring to the table. That’s why in this article we’ll delve into:

  • The discussion between SCADA and IIoT
  • What is SCADA and IIoT?
  • Key differences between SCADA and IIoT
  • Insights and trends by an experienced system integrator

This will equip you with the knowledge needed to understand the differences between SCADA and IIoT and have a better idea of what you want. And if this article doesn’t answer your questions, send us a quick email. We’ll be happy to help!

Understanding the SCADA and Industrial IoT Discussion

So, what’s sparking this conversation?

Why is there an ongoing discussion between SCADA and IIoT for supremacy?

Well, both SCADA and IIoT are industrial control systems (ICS). According to a Global Industry Perspective and Forecast report by Zion Market Research, the industrial control systems market is expected to reach 181.6 USD billion in 2024.

Government entities are partnering with CISA (Cybersecurity & Infrastructure Security Agency) to encourage the adoption of automation across industries. Moreover, the growth of industrial infrastructure in developing countries like India and China propels this trend.

Naturally, numerous industries want to determine what’s the best solution they can invest their money in. After all, paying for ICS can be costly. For example, the price of a small to medium-sized SCADA system could be anywhere between $10,000 and $100,000.

But here’s the deal: SCADA has a long-standing history of successful implementation in various industries. It has proven to be a trusted choice in monitoring critical parameters, alerting of anomalies, and automating processes. Its legacy is rooted in its ability to deliver operational stability and reliability, which are crucial pillars of industrial processes.

On the other hand, IIoT invites innovation and is one of the latest buzzwords that promise transformative potential. By interconnecting devices, analyzing vast data streams, and offering predictive insights, IIoT holds the promise of ushering industries into a new era of data-driven decision-making and optimized operations.

 As you can see, the ongoing discussion between SCADA and IIoT isn’t just a debate. It’s about striking the right balance between historical successes and future possibilities.

What Is Industrial IoT?

IIoT is another ICS that integrates internet connectivity into the core operations of the industrial landscape. It consists of a network interlinking smart devices, machinery, and systems.

IIoT accumulates tons of data to create a digital representation of operational processes. Thanks to its use of big data analytics you can identify trends, anomalies, and inefficiencies. This results in informed decisions to optimize processes, cut downtime, and even predict potential equipment failures.

IIoT undertakes duties like:

  • Asset tracking to optimize inventory management
  • Predictive maintenance to reduce downtime
  • Monitoring of energy efficiency to cut costs
  • Optimization of processes to streamline operations

5 Key Differences Between SCADA and Industrial IoT

We already gave you the definitions of SCADA and IIoT. But this blog post wouldn’t be complete without understanding what makes each of these systems different.

Here’s a list of key differences that could guide your preference.

#1. Architecture: Centralized vs. Decentralized

SCADA relies on a centralized architecture, where a central server controls and monitors data from multiple field devices. In contrast, IIoT employs a decentralized architecture, where devices communicate directly or through edge computing, reducing reliance on a central hub.

For example, a water treatment plant using SCADA might have a single control center. However, an IIoT-capable fleet of delivery trucks communicates directly with each other to optimize routes without centralized control.

#2. Data Processing: Real-Time vs. Big Data Analytics

SCADA specializes in real-time data processing, so data is available as soon as it’s collected in real time. This allows operators to quickly react to immediate operational changes and avoid any unwanted consequences.

(It’s worth noting that SCADA systems also have a historian component but they aren’t purpose-built for data historization)

IIoT excels at handling large amounts of data for analysis. It focuses on big data analytics to uncover trends and patterns to help make data-informed decisions. This helps you predict potential issues and promotes a proactive approach to solving problems.

Let’s say that a manufacturing line monitored by SCADA can quickly adjust to changes in production speed. But IIoT might analyze historical data to optimize long-term efficiency.

#3. Communication Protocols: Proprietary vs. Standardized

SCADA systems often rely on proprietary communication protocols. To exchange data or to communicate, you’ll have to use specialized protocols, formats, or standards specific to the product or technology. This gives you better performance when exchanging data but also has limitations if you want to connect to products from other vendors.

IIoT has standardized protocols like MQTT or HTTP which facilitates interoperability between diverse devices. These protocols are universally accepted, which means multiple devices can communicate and work together regardless of the vendor.

Let’s say you’re in a plant with machinery from different vendors. If you’re using SCADA and a problem arises, the maintenance team would need to be well-versed in each protocol to troubleshoot effectively. But if you’re using IIoT, the maintenance team can diagnose the issue without specialized knowledge for each device.

#4. Scalability: Traditional vs. Cloud Solutions

Traditionally, SCADA systems are tied to hardware upgrades to expand their capacity. This involves installing additional servers, sensors, or controllers. However, some SCADA systems can run in virtual environments like Microsoft Hyper-V and VMware vSphere.

Still, the hardware-based approach in SCADA systems allows for a more controlled and predictable expansion as you have established protocols and practices. The only downside is that, as the system grows, maintenance can become costly.

IIoT typically uses cloud computing for scalable solutions. When you need more devices, you can easily integrate them into the cloud, which acts as a centralized hub for processing and storage.

#5. Security: Isolated vs. Cybersecurity-Centric

SCADA systems use physical or network isolation to ensure the security of their cloud environment and hardware components. Network segregation using firewalls or having a business network is a best practice for SCADA systems. And, if you have a control room in which you don’t want unauthorized personnel to enter, you can use locks or any other kind of physical security enhancement.

IIoT has a web-connected nature; it uses cybersecurity methods to secure data transmission. Some of these methods include encryption and authentication. As IIoT devices often communicate through public networks, rigorous cybersecurity protocols are implemented to mitigate the risks of cyberattacks.

Industry Insights and Future Trends: A Conversation With Paula Talley

We sat down with Paula Talley, an expert System Integrator with over 20 years of hands-on experience. Paula’s deep understanding of SCADA and IIoT allowed her to share invaluable insights into the evolving landscape of industrial control.

Here are her answers to the SCADA vs. Industrial IoT debate.

How do SCADA systems traditionally operate, and how does Industrial IoT change or enhance this approach?

Traditionally, SCADA helps companies operate a plant or particular process. Even though technological advancements have allowed SCADA to run on virtual environments, information is (generally) still gathered on a local basis. When you use a SCADA system, it gathers information from sensors to display it in an HMI (Human Machine Interface). You’re able to exert limited control into a single destination like starting a process, stopping a pump, or closing a valve.   Complexities arise when there’s a need for data that doesn’t fall under the umbrella of ‘critical’ for daily operations, like monitoring the pressure at the bottom of a well. Such data serves more analytical purposes, typically coming into play when something requires fixing. Unfortunately, it remains inaccessible to individuals outside the facility. This is where IIoT can help. IIoT information can easily be made available for use in the cloud or other various applications. If someone wants to see data from a particular machine, they easily can. And when you integrate IIoT into your SCADA system, you get an augmented system for data accessibility.

What are some current trends you’re observing in the adoption of SCADA and Industrial IoT technologies?

A notable trend is a shift towards SCADA systems sourcing their data from IoT processes, rather than establishing direct connections with devices. This transition is driven by the need for enhanced data accessibility and streamlined communication. Also, the rise of MQTT as a preferred communication protocol pushes this trend further.
“There’s a project I’m finishing up for a client, where we’re leveraging the strengths of both SCADA and IIoT. Operators and users of the system have noticed a significant improvement. It operates much faster, with data refreshing at an accelerated pace. The implementation of MQTT allowed us to get rid of all these point-to-point VPN connections. Now, everything works securely over the Internet. It’s a much simpler and more streamlined process for them.”
IIoT stands out for its speed in adding new capabilities, while SCADA requires careful consideration of local systems before making changes. This shift towards IoT-based data collection represents a significant step forward in modernizing industrial automation.

Will Industrial IoT Eventually Replace SCADA?

While IIoT brings remarkable advancements, SCADA systems won’t go away. They serve a distinct purpose by ensuring precise operation and monitoring of critical assets. However, not every company needs a SCADA system. For simpler industrial applications, a less complex and costly solution is enough.

IIoT and SCADA aren’t competitors. Both IIoT and SCADA have their place, proving that in industrial automation, there’s no one-size-fits-all. The choice of using one over the other depends on the complexity and cost of the solution.

Which One Is Better for You?

So, it all comes down to this. From the ongoing discussion and diverse approaches of IIoT vs SCADA in managing industrial processes, you can perceive each ones strengths and downsides.

However, it’s worth reiterating that SCADA and IIoT aren’t mutually exclusive. These technologies fulfill different needs in the marketplace but can work together to enhance your industrial processes.

Here’s a more specific answer to which one is better for you according to your needs.

SCADA is best for you if you:

  • Have a legacy system that can be integrated with SCADA to modernize your processes without starting from scratch.
  • Work in an environment of fast-paced operations as SCADA’s real-time control quickly adapts to immediate changes.
  • Focus on real-time control but don’t need extensive historical data analysis.
  • Need customized control tailored to specific operations.

IIoT is best for you if you:

  • Work in an industry where data-driven insights are the cornerstone for informed decisions.
  • Want to embrace cloud-based adaptability to cope with scalable growth and changing demands.
  • Consider leveraging cross-device functionality as an important feature for collaborative ecosystems.
  • Want to adopt proactive maintenance for your equipment with data analysis.


Need to move a SCADA project forward with MQTT? Let’s talk!