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Automation Engineer Interview Questions That Matter

Updated: Jul 21, 2023

10 Important Automation Engineer Interview Questions And Answers

Automation Engineer Interview Questions And Answers

Can you explain the concept of SCADA? How does it work in an industrial automation setting and what are its key advantages and limitations?

Why is this question asked?

Understanding SCADA is fundamental to working in automation engineering as it's a standard system used across industries.

This question gauges your knowledge about SCADA, its operation, and its implications in an industrial environment.

Example answer:

As an automation engineer, I've often used Supervisory Control and Data Acquisition (SCADA) systems in my projects.

SCADA is a robust system that allows for centralized control and monitoring of an entire plant or facility, from a single location. It is widely employed in diverse sectors including energy, oil, gas, water, and manufacturing, among others.

SCADA primarily works by gathering data from remote locations, transmitting it to a central site, and then facilitating the management of this data.

In a typical industrial setting, SCADA systems are typically comprised of several components. First, you have the field instrumentation which includes sensors, transmitters, and actuators.

This instrumentation is in charge of collecting and sending data related to process variables, such as temperature, pressure, flow rate, etc., from the field to the SCADA system.

The next critical component of SCADA systems is the Remote Terminal Units (RTUs) or Programmable Logic Controllers (PLCs). These devices serve as the intermediary between the field instrumentation and the central computer system.

They receive the signals from the field instruments, convert these signals into digital data, and transmit them to the SCADA system.

At the core of SCADA lies the central computer system. This system decodes the incoming data and presents it in a human-readable form, often as graphs or charts.

SCADA software often includes functionalities that allow for alarms, trending, diagnostics, and management of plant operations.

One key advantage of SCADA is the ability to remotely control industrial processes. It reduces the need for manual monitoring and adjustment of process variables, thereby increasing efficiency, reducing errors, and enhancing safety.

Also, SCADA systems provide excellent data logging and archiving capabilities, which can aid in optimizing operations and troubleshooting.

That being said, SCADA systems also have their limitations. They can be complex to set up and require a significant investment of time and resources.

They also have inherent cybersecurity vulnerabilities because they connect to a wide array of devices across various locations. If not properly protected, these systems can be susceptible to hacking, potentially leading to catastrophic results.

Why is this answer good?

  • The response demonstrates a comprehensive understanding of SCADA systems, showing both theoretical and practical knowledge.

  • It outlines SCADA's role and importance in an industrial setting, explaining its components, benefits, and limitations.

  • It provides examples from the candidate's own experience using SCADA, revealing their hands-on experience with automation systems.

  • The answer addresses potential concerns like cybersecurity, indicating that the candidate is aware of the broader implications of SCADA systems.

Please explain how you would design a fault-tolerant automation system. What considerations would you take into account to ensure minimal downtime and maximum operational efficiency?

Why is this question asked?

Fault tolerance is a critical aspect of automation systems design, ensuring system reliability, availability, and continuity of operation.

This question evaluates your understanding of fault tolerance, your design approach, and your ability to create systems that ensure minimal downtime and maximum operational efficiency.

Example answer:

In designing a fault-tolerant automation system, the central principle is to ensure that the system can continue to function correctly even when some components fail. There are several factors I consider to ensure minimal downtime and maximum operational efficiency.

First off, redundancy is crucial. Having redundant components means that if one part of the system fails, there are backup components that can take over its function.

There are different strategies for redundancy, including hot, warm, and cold redundancy. I consider the system's criticality and budgetary constraints in deciding the redundancy strategy.

Secondly, I ensure that the system can detect and isolate faults quickly and accurately to prevent propagation.

This is usually done through comprehensive monitoring systems that constantly check the state of the system components and trigger alarms in case of any deviations from the expected performance.

In terms of software, I tend to use fault-tolerant design patterns such as circuit breakers or retry patterns.

These patterns allow the system to handle exceptions gracefully and provide an opportunity for failed operations to be retried, thereby minimizing disruption to the overall system operation.

Next, I consider the inclusion of predictive maintenance capabilities, employing techniques such as machine learning to predict possible faults based on historical data. This allows for proactive maintenance, which can reduce both downtime and maintenance costs.

Another crucial factor is the design of an efficient failover mechanism. A good failover mechanism should be able to switch to the redundant system quickly and smoothly without causing significant service disruption. This usually requires careful planning and testing.

Finally, I always document and keep track of potential failure points and ensure that the system has been thoroughly tested to handle these faults.

This includes conducting stress testing and chaos engineering to simulate failures and verify the system's behavior under these conditions.

Why is this answer good?

  • The answer shows a clear understanding of the principles and practices involved in designing a fault-tolerant system.

  • It outlines a systematic approach to design, emphasizing critical factors like redundancy, monitoring, and predictive maintenance.

  • The candidate demonstrates awareness of both hardware and software considerations, highlighting a holistic approach to system design.

  • The answer shows the candidate's proactive approach towards potential failure points, stress testing, and chaos engineering, which can prevent future operational problems.

Explain the importance of PID control in automation. How would you tune a PID controller for optimum performance?

Why is this question asked?

PID controllers are fundamental components in automation systems, responsible for maintaining system variables at desired levels.

The interviewer wants to gauge your understanding of PID controllers, their significance in automation, and your practical skills in tuning them for optimal performance.

Example answer:

Proportional-Integral-Derivative (PID) controllers are one of the most common types of feedback controllers used in automation systems, thanks to their simplicity, effectiveness, and versatility.

They play a key role in maintaining a system's output at a desired set point in spite of disturbances.

A PID controller works by calculating an "error" value as the difference between a measured process variable and the desired set-point.

The controller attempts to minimize this error over time by adjusting the process control inputs.

The PID controller's three separate parameters - proportional, integral, and derivative - each correct the error in different ways, and together, they provide a more accurate and stable control over the system.

The proportional term (P) depends on the present error, the integral term (I) accumulates past errors, and the derivative term (D) predicts future errors based on current rate of change.

Tuning a PID controller is an art as much as a science. It involves adjusting the proportional, integral, and derivative gains to achieve the desired system response.

There are different methods of tuning a PID controller, including manual tuning, the Ziegler-Nichols method, Cohen-Coon method, and software-based optimization, among others.

If I were to tune a PID controller, I would first start with setting integral and derivative gains to zero, and increase the proportional gain until the system starts to oscillate.

This is the critical gain.

Then, I would measure the oscillation period and use these two values as initial parameters to apply the Ziegler-Nichols or another tuning rule, depending on the desired system response.

However, these methods only provide a starting point. After the initial tuning, I would check the system's response to changes in the set point and load disturbances, and adjust the PID parameters iteratively until an optimal performance is achieved.

This process usually requires a balance between responsiveness and stability.

Also, tuning should be redone periodically, as system dynamics may change over time. In addition, advanced systems may require adaptive or gain-scheduled PID controllers that adjust the PID parameters in real-time based on the operating conditions.

Why is this answer good?

  • The answer shows a deep understanding of PID controllers and their role in automation systems.

  • The candidate demonstrates knowledge of various tuning methods and an iterative approach to achieve optimum performance.

  • The answer reveals the candidate's awareness of real-world challenges, like changing system dynamics and the need for adaptive control.

  • The candidate’s description of the tuning process shows their practical experience with PID controllers.

How would you handle PLC programming for a complex manufacturing process? Could you give us an example of a challenging project that required intricate PLC programming?

Why is this question asked?

Your interviewer wants to assess your expertise in PLC programming, particularly in handling complex manufacturing processes.

This is an opportunity to demonstrate your problem-solving skills, creativity, and ability to deliver effective solutions in challenging situations.

Example answer:

So, PLC stands for Programmable Logic Controllers, and for successful PLC programming, I’d say that the first step is to fully understand the manufacturing process.

I usually work closely with process engineers, operators, and other relevant personnel to grasp the process intricacies. A complete understanding ensures the creation of an accurate control philosophy.

Once I have a clear picture of the process, I proceed to design the control logic.

I prefer using a structured approach for this, using subroutines and function blocks whenever possible. This helps in managing complexity and allows for easier troubleshooting and modifications in the future.

One challenging project I remember involved a large food processing plant. The plant had multiple manufacturing lines running simultaneously, with varying production requirements, timing sequences, and strict safety regulations.

The complexity was in the interdependence of the manufacturing lines. An issue in one line could potentially disrupt the whole process.

Also, since this was a food processing plant, we had to ensure the highest level of hygiene and safety, which added to the programming complexity.

After a thorough study of the processes and close interactions with the plant operators, we decided to use a combination of Sequential Function Charts (SFCs) and Function Block Diagrams (FBDs) for the programming.

SFCs were ideal for managing complex sequences and dependencies, while FBDs were used to represent the control loops for individual equipment.

We spent considerable time testing the program in a simulated environment before deploying it in the live system. Post-deployment, we carried out a detailed commissioning process, which included making minor adjustments in the program based on the actual performance.

This project was a great learning experience. It not only tested my technical skills but also highlighted the importance of teamwork and detailed planning in managing complex manufacturing processes.

Why is this answer good?

  • The answer demonstrates a systematic and structured approach to handling complex PLC programming tasks, showing the candidate's problem-solving skills.

  • The candidate provides a real-life example, giving insight into their practical experience and ability to handle challenging projects.

  • The response shows the candidate's understanding of the importance of teamwork, planning, and testing in ensuring successful project outcomes.

  • The candidate's emphasis on safety and regulations in their project showcases their conscientiousness and attention to critical details.

Could you explain how you use artificial intelligence and machine learning in your automation projects? What benefits and challenges have you encountered?

Why is this question asked?

The idea is to assess your proficiency in integrating modern technologies like AI and machine learning into traditional automation systems.

Your experience in overcoming related challenges and leveraging benefits is crucial to demonstrate your adaptability and innovative thinking in the evolving automation landscape.

Example answer:

In my experience, artificial intelligence (AI) and machine learning (ML) can significantly enhance automation systems, leading to improved efficiency, predictive capabilities, and adaptability. But the integration also brings a few challenges.

One project where I used these technologies was for an automated quality control system in a manufacturing plant.

The aim was to detect defects in the products in real time.

For this, we used a combination of machine vision and machine learning algorithms. Images of the products were captured using high-resolution cameras, and these images were then processed by an ML algorithm trained to identify defects.

This AI-enabled system could identify defects with much higher accuracy and speed than human inspectors, significantly improving the quality control process.

The benefit of using AI and ML in this context was evident. We reduced human error, increased inspection speed, and improved overall product quality.

But it wasn't without its challenges. Collecting and labeling the initial set of training data was a time-consuming process.

Also, the ML model needed continuous updating and refining to maintain its accuracy, which required a systematic approach to collect and incorporate feedback.

Another interesting application of AI in my projects has been predictive maintenance. By analyzing historical operational data using ML algorithms, we've been able to predict potential failures before they occur, thereby minimizing downtime and maintenance costs.

However, such applications also require a large volume of quality data, and gathering such data can be a challenge. Also, translating these predictions into actionable maintenance tasks is another challenge that requires careful planning and coordination.

Why is this answer good?

  • The candidate provides specific examples of how AI and ML can be applied in automation projects, demonstrating their practical experience and innovative thinking.

  • The answer shows an understanding of the benefits AI and ML can bring to automation, as well as the challenges associated with their implementation.

  • The candidate shows awareness of the multidisciplinary nature of modern automation projects, highlighting their ability to work in cross-functional teams.

  • The response demonstrates the candidate's adaptability in integrating new technologies into traditional systems, an essential skill in the rapidly evolving field of automation.

Describe the steps you would take to integrate a new piece of hardware into an existing automation system. What types of compatibility issues might you anticipate and how would you overcome them?

Why is this question asked?

The interviewer wants to know your expertise in system integration, an essential task in automation engineering.

The goal is to test your ability to foresee potential issues, plan effectively, and problem-solve in real-time, key attributes for ensuring seamless system integration and functionality.

Example answer:

The first step would be to understand the specifications of the new hardware and how it is expected to interact with the existing system. This requires studying the technical manuals and, if possible, consulting with the manufacturer's technical support team.

The next step is to review the existing automation system, including its capabilities, limitations, and the interfaces it supports. Compatibility is a crucial aspect here; the new hardware must be compatible with the system's current interfaces, protocols, and power requirements.

Next comes the design phase. This involves planning the integration process, including the hardware setup, wiring, and configuration. This phase may require designing new control logic or modifying existing logic to accommodate the new hardware.

The physical installation of the hardware follows. This involves carefully installing the hardware, making sure it is securely fixed and correctly connecting all the necessary cables and wires.

After the hardware installation, the control logic is updated and tested. During this stage, it's essential to have a robust rollback plan in case issues arise that cannot be resolved immediately.

Then comes the commissioning phase, where the new hardware is tested in conjunction with the overall system. This should be done under various operating conditions to ensure that the system performs as expected in all scenarios.

Potential compatibility issues that could arise include mismatched communication protocols, incompatible software versions, or different power requirements.

These can be overcome by using protocol converters, updating or patching the software, or using power adapters or transformers, respectively.

But the best way to deal with compatibility issues is to anticipate them during the planning phase and select hardware that is fully compatible with the existing system.

Lastly, documentation is crucial in any system integration process. All changes made to the system, including hardware additions, logic changes, and configuration settings, should be thoroughly documented for future reference.

Why is this answer good?

  • The candidate shows a systematic and comprehensive approach to hardware integration, highlighting their thoroughness and attention to detail.

  • The response illustrates the candidate's ability to anticipate potential compatibility issues and provide solutions, demonstrating their problem-solving skills.

  • The emphasis on documentation shows the candidate's understanding of its importance in managing complex systems and facilitating future troubleshooting or system upgrades.

  • The mention of a rollback plan exhibits the candidate's foresight and preparedness for potential problems during the integration process.

Can you provide a high-level overview of how you would automate the process of quality assurance in a manufacturing setting?

Why is this question asked?

The interviewer wants to evaluate your understanding of quality assurance automation, especially in a manufacturing environment.

They’re looking to assess your ability to conceptualize, design, and implement automation solutions for complex, real-world problems, particularly those related to maintaining product quality.

Example answer:

The overall goal would be to create an automated system that can detect defects, track quality metrics, and adapt to changes in the manufacturing process.

The first step is to understand the manufacturing process and define what constitutes a quality product.

This could be based on dimensions, appearance, material properties, or any other relevant parameters. We’d need to work closely with the quality assurance team and process engineers to define these parameters.

Once we've defined what we're looking for, we can design a system to detect and measure these parameters.

This could involve a combination of sensors, machine vision systems, and data acquisition systems.

For example, vision systems could be used to inspect the appearance of products, while sensors could measure dimensions, temperatures, pressures, or other physical properties.

These data acquisition systems would be connected to a central control system, typically a PLC or a similar device.

The control system would process the data in real time and determine whether each product meets the defined quality standards. Products that fail to meet these standards could be automatically removed from the production line.

In addition to real-time quality control, we could also implement a data analysis system to track quality metrics over time. This could involve storing quality data in a database and using statistical analysis software to monitor trends and detect changes in product quality.

Machine learning algorithms could also be incorporated to adapt to changes in the manufacturing process.

For example, if the system detects a consistent deviation from the desired quality parameters, it could automatically adjust the manufacturing process to compensate for this deviation.

As with any automated system, thorough testing is the make-or-break factor, here. We’d have to run the system with a variety of products, under different operating conditions, to ensure that it can reliably detect defects and maintain product quality.

Why is this answer good?

  • The candidate demonstrates a good understanding of quality assurance in a manufacturing environment and how automation can enhance it, showing their knowledge and innovation skills.

  • The answer exhibits a systematic approach to designing and implementing an automated quality assurance system, showcasing their project planning and execution capabilities.

  • The candidate's consideration of machine learning algorithms for adaptive quality control indicates their familiarity with modern technologies in automation.

  • The emphasis on testing the system under various conditions reflects the candidate's thoroughness and commitment to delivering reliable automation solutions.

What security measures do you implement to ensure the safety and reliability of your automated systems, especially in the context of increasing cybersecurity threats?

Why is this question asked?

Your interviewer wants to gauge your understanding of the security risks inherent to automated systems and the measures you take to mitigate them.

As automation systems become more interconnected and cyber threats continue to evolve, your ability to ensure system safety and reliability is of paramount importance.

Example answer:

First, I make sure to incorporate security by design during the system development phase.

This approach considers security aspects at the design and architecture level rather than as an afterthought.

It includes strategies like network segmentation, where the automation system is isolated from the general IT network, and minimization, where only essential components and services are included in the system.

Second, I advocate for robust user management practices. This includes unique user IDs for all users, strong password policies, and role-based access control, where users are only given access to the system functions they need to perform their roles.

Additionally, I prioritize keeping all system software, including operating system, application software, and firmware, up-to-date.

Regular software updates not only provide new features and performance improvements, but they also often include patches for known security vulnerabilities.

An intrusion detection system (IDS) is also an integral part of my security strategy. IDS helps identify any abnormal activities or intrusion attempts on the network, which can then be dealt with promptly to prevent any potential damage.

Moreover, I strongly recommend regular audits and vulnerability assessments. Regular audits can identify any gaps in the security measures, and vulnerability assessments can find potential weak points in the system that could be exploited by attackers.

Lastly, given the increasing prevalence of sophisticated cyber threats, I find it beneficial to have a disaster recovery plan in place.

This plan outlines the steps to be taken in the event of a security breach or system failure to restore the system to normal operation with minimal downtime.

Why is this answer good?

  • The candidate demonstrates a holistic understanding of system security, covering aspects from system design to emergency response, showing their comprehensive approach to system safety.

  • The answer reflects the candidate's awareness of the current landscape of cybersecurity threats and the importance of staying ahead of potential risks.

  • The mention of specific strategies such as network segmentation, intrusion detection systems, and disaster recovery planning indicates their practical knowledge and experience in implementing security measures.

  • The candidate underscores the importance of regular system audits and vulnerability assessments, illustrating their commitment to maintaining system integrity over time.

Can you tell us about a time when an automation project you were working on faced significant hurdles? How did you overcome these challenges and what was the outcome?

Why is this question asked?

This is essentially a test of your problem-solving skills, resilience, and adaptability in the face of challenges.

Your ability to navigate difficulties, especially within the often complex and unpredictable world of automation projects, reflects on your overall competency as an automation engineer.

Example answer:

A few years back, I was leading an automation project for a large manufacturing company. The aim was to automate the entire assembly line using robotics and advanced PLC systems.

However, we faced significant hurdles during the implementation phase.

One major challenge was integrating the different components of the assembly line. We had various machines from different manufacturers, each with its proprietary control system. Aligning these disparate systems was a daunting task.

Also, the assembly line was a high-throughput process, so we had to maintain production levels while transitioning to the automated system.

To address these challenges, we adopted a phased approach. Instead of trying to automate the entire assembly line at once, we divided the project into manageable modules. This approach allowed us to focus on one section at a time and thoroughly troubleshoot any issues that arose.

The integration of different control systems required significant research and collaboration. We had to study different industrial protocols and engage in extensive dialogue with the equipment manufacturers.

In the end, we decided to use an advanced PLC with multi-protocol capabilities that could communicate effectively with all the machines.

To maintain production levels during the transition, we scheduled major changes during off-peak hours and weekends. We also developed contingency plans to quickly revert to the manual process if any critical issues arose during the automation process.

Despite the challenges, the project was a success. The phased implementation minimized disruptions to the production process, and the advanced PLC we used effectively integrated the different machines.

The results were great, actually. The automated assembly line improved the company's production efficiency by 30% and significantly reduced manual errors. It was challenging. But it was also a very rewarding experience that honed my problem-solving and project-management skills.

Why is this answer good?

  • The candidate demonstrates their ability to handle significant challenges in a large-scale automation project, reflecting their resilience and problem-solving skills.

  • Their approach of breaking down the project into manageable modules indicates their strategic thinking and project management capabilities.

  • The ability to maintain production levels during the transition shows their flexibility and consideration for business operations.

  • The successful outcome, despite the hurdles, illustrates their tenacity and ability to deliver under challenging circumstances.

Describe a situation where you had to innovate or think outside the box to solve a complex problem in an automation project. What was the issue and how did your solution impact the end result?

Why is this question asked?

This question is designed to assess your ability to think creatively and innovate under pressure.

In the rapidly evolving field of automation engineering, being able to generate novel solutions to complex problems is a highly valued skill that can greatly influence project outcomes.

Example answer:

There was an instance when I was working on an automation project for a pharmaceutical client.

The goal was to automate the process of filling vials with a high degree of precision. The challenge was that the liquid medicine was sensitive to temperature variations, which was affecting the precision of the filling process, leading to inconsistencies.

Traditional approaches to this problem might have involved increasing the precision of the filling machinery or adjusting the temperature of the environment, both of which had significant cost implications.

However, we needed a more innovative, cost-effective solution.

I proposed the idea of using a temperature-compensation algorithm within the automation system.

Instead of trying to maintain a constant temperature, which was proving to be costly and inefficient, we would monitor the temperature continuously and adjust the fill volume in real-time to compensate for the temperature-related variations.

After getting the approval for this outside-the-box idea, I worked with my team to develop the algorithm and integrate it into the PLC controlling the filling process.

We used a combination of historical data, predictive modeling, and real-time temperature data to dynamically adjust the fill volume.

The implementation of the temperature-compensation algorithm was a resounding success.

It not only solved the issue of fill volume variations but did so in a cost-effective manner. The fill precision improved by 20%, and the solution significantly reduced the need for costly environmental controls.

This instance taught me the power of creative problem-solving in automation engineering and its potential to deliver impactful results.

Why is this answer good?

  • The candidate illustrates their ability to innovate and think creatively when faced with a challenging issue, a valuable skill in automation engineering.

  • The proposed solution was not just effective but also cost-efficient, showing the candidate's ability to consider and optimize multiple project parameters.

  • The candidate's ability to successfully implement an innovative solution demonstrates their technical skill and effectiveness in driving results.


There you have it — 10 Important Automation Engineer interview questions and answers. Now, we’ve gone through only ten questions because we have elaborate, in-depth answers for each question. Within these answers, we’ve also answered a few smaller, simpler questions.

And no interviewer is going to ask you a hundred basic questions anyway.

Use this blog as a guide and great jobs shouldn’t be too far away.

On that front, if you’re looking for an Automation Engineer job, check out Simple Job Listings. We only list verified, fully-remote jobs that pay well. What’s more, most of the jobs that we post aren’t listed anywhere else.

Visit Simple Job Listings and find amazing remote Automation Engineer jobs. Good luck!



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