For decades, programmable logic controllers (PLCs) have been at the core of most automated systems, having been pioneered in the automotive industry in the late 1960s. They are well known for their durability and ability to withstand harsh operations conditions.
Embedded systems, on the other hand, have been shown to perform the same functions at a fraction of the cost of PLCs, utilizing printed circuit boards inside the machines they control, while using less hardware and no cables.
In your product development process, how do you choose the best option? The answer isn’t as simple as lining up the pros and cons. There are many important factors to consider, and I’d like to outline seven considerations that you should account for when evaluating your options. I need to stress though, whatever you choose, do it early in the product development cycle.
The key is understanding your needs and finding the best solution to meet those needs.
- Return on Investment (ROI) - An embedded system relies on higher volume production to achieve ROI targets, understanding that this approach relies heavily on Non-Recurring Engineering (NRE) costs which will be much more than with PLC. With a PLC, your entry costs are lower because the work is pretty much done. However, your lifecycle cost or lifetime cost will be higher because of the significantly more expensive design of the PLC.
- Skillset - In the embedded and PLC spaces, the skillsets required are very different. In the embedded space, you're going to need an electrical engineer, an embedded software and/or firmware engineer, and an engineering manager. You can accomplish with your own staff or outsource to a company like USA Firmware. In a PLC design, the electronics piece is already done. The critical skillset in this circumstance is someone who can develop a software-level application.
- Maintenance - With an embedded solution, you have to maintain the electronics and the firmware. In addition, it is important to have a process in place to manage parts obsolescence or parts availability for the lifespan of the board which is about 10 years. One of the main advantages of PLCs is their ease of maintenance since they are outside of the machine they control. When an issue does arise, it’s really the PLC manufacturer’s issue, not yours. PLCs are designed in such a fashion to live a long time, whereby you’re probably not going to have to go through a new design turn for a good 20 years.
- Spare Parts - In an embedded scenario, you are going to need engineers, such as manufacturing engineers, to manage that product lifecycle as well as the processes in place to do so. Something to keep in mind. If your spare parts business is an important component of your overall profitability, an embedded solution's going to work to your advantage. With a PLC solution, you are at the mercy of the manufacturer's distribution channels where you won’t have much or any kind of a profit margin because of the overall large cost of a PLC.
- Design Flexibility - With an embedded solution, you own the design. You've designed and developed it from the ground up--the electronics, the software, and the firmware. As a result, it becomes an extremely flexible platform. When you want to make a change, you have control over all aspects at a very micro level. With a PLC, you're dealing primarily with an off-the shelf black box and as a result, your flexibility is substantially reduced.
- Emergency response - Emergencies are bound to happen at customer sites. With an embedded solution, you're going to need to have staff engineers that can quickly address those issues. You also need to have a process in place to be able to manage that. A PLC solution can be easy to program and maintain, yet you'll see at times it creates latent bugs. However, the customer's manufacturing facility may be able to make the change quickly because of the different skillset needed to make the fixes.
- Cost - If the PLC solution is a large percentage of the overall cost of your product, you really need to think about embedded. At first glance, you may be thinking you can handle PLC fairly easily without having to outsource any of the work. However, it can be an enormous piece of your overall product costs. That’s when you need to deeply assess and weigh which option is better for your needs.
Both choices make great options in the right scenario. Take your time and weigh these considerations carefully to see if an embedded system might be what you need for your company.
I welcome your thoughts on this. If you take the right steps, do your homework, and make a decision early in the product development cycle, you will be glad you took that time to make the smart decision for your company.
Follow and message me on LinkedIn and let us know what you think. And connect with me if you would like to learn more about USA Firmware and how our Design Services and Talent Solutions teams can bring your vision to life with the right solutions and people.
Bob Scaccia
Bob Scaccia, President, CEO and founder of USA Firmware, formed the company in 2011 out of his passion for the art firmware design. Bob graduated with a BSEE in Electrical Engineering and quickly built a career that would lead him to become an expert in his field and a visionary entrepreneur in the industry. His past work experience includes design management and leadership roles in firmware with organizations Raytheon, Philips (formerly Picker International), Keithley Instruments and Thermo Scientific. Since founding USA Firmware, Bob has grown the organization from a $200,000 per year business to a multi-million-dollar, award-winning business today. In addition, Bob is a firmware influencer and powers the world's largest embedded firmware group, as well as a firmware contributor with articles and podcasts on embedded.com. He's also published several articles including, "What a firmware curriculum would look like" and has been interviewed by various radio personalities on the topic of firmware and the embedded future.
