Considerations When Navigating Build or Buy Decisions for ...

04 Aug.,2025

 

Considerations When Navigating Build or Buy Decisions for ...

Understanding the total cost trade-offs of building or buying is a difficult but important task. Of course, you must account for cost of your bill of materials (BOM), but there is a lengthy list of short- and long-term costs associated with custom board design that are not always well accounted for.

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No design manager wants to be in a situation where the cost of development is underestimated to the point where the project is no longer profitable. But the reality is that development time (and, therefore, cost) is often underestimated—only 41 percent  of embedded projects finish on schedule.

To help you better understand total cost of ownership, here’s a summary of the costs that go into a full-custom control board design:

  • Development:
    • Hardware design
    • Software development (Including including software stack selection, integration, and verification)
    • Mechanical design
    • Selection and management of component vendors
    • Test (including software and hardware test and verification, system performance testing, environmental certifications, shock and vibration, and thermal validation)
    • System integration
    • Documentation
    • Design tools (if you don’t already have them)
  • Manufacturing:
    • Tooling
    • Assembly cost
    • Production test
  • Component Cost
    • BOM
  • Sustaining Engineering
    • Inventory management (this could involve re-designs as components go end-of-life, or cost of keeping an inventory of spares)
    • Software maintenance (OS and driver maintenance, regression testing)
    • Customer support
    • Upgrade cost
    • RMAs

These are a lot of costs to consider! Compare this to a commercial off-the-shelf (COTS) solution. Commercial vendors can not only save you development cost, but also typically use their buying power to purchase components at a much lower price, because they are typically buying in much higher volumes.

Commercial vendors can also off-load sustaining engineering costs. For example, NI’s strong vendor relationships gives us insight into roadmaps that most of our customers don’t have access to. We pass this foresight on to our customers by designing products with very long product life cycles (15 years for CompactRIO products) and seamless upgrade paths. For industrial applications with long field deployments, this type of support is critical.

If a commercial vendor can reduce cost through commoditization, is there ever a situation when the cost of developing in-house would be lower? When evaluating a COTS product that seems too expensive, you should ask:

  • Will I only use a small percentage of the features this product offers?
  • Will I have to “design around”  this product in a way that significantly increases development cost, because it doesn’t fit well into the system?

If the answer to either of these questions is “yes,” the COTS product may be too expensive because it’s just not the right product for you. If the answer is no, it’s probably time to take a hard look and evaluate if you are underestimating your costs, particularly sustaining costs, as these tend to be most overlooked.

End-product volume considerations tie in closely with cost considerations. Most design managers understand that at lower quantities, COTS solutions become more appealing. However, it’s too simplistic to have a blanket threshold and apply it to every build versus buy decision.

The key is determining the “crossover point” where building becomes more profitable than buying. In other words, where the nonrecurring engineering (NRE) cost can be amortized over a large enough quantity that the development cost per unit is offset by savings in component cost. The better you understand all the costs (including sustaining engineering), and factor in the risk of budget and time overruns, the better idea you have of what the true crossover point is.

Keep in mind that most vendors have a pricing strategy for OEM customers that will allow them to scale down prices for higher quantities. This cost savings must also be factored in when evaluating cost.

It is nearly always quicker to buy COTS than to build a custom design.

However, while likely still faster than full-custom design, many COTS options may require a significant amount of software development to maneuver around fixed, vendor-defined functionality.

At NI, the customizability of our platform makes us especially adept at reducing development time, even when compared to other COTS options. On average, design teams who use the NI toolchain complete their projects in about half the time with design teams that are less than half the size. For example, energy storage company, Dynapower, accelerated their development time from 72 weeks to 24 weeks using the NI platform .

There are more advantages to faster development than saving on engineering cost. Getting your product to market faster often leads to increased market share and gives you an advantage over your competitors. In industries where innovation and competition is high, time to market may be critical for your project's success. 

You must also consider the opportunity cost that comes with longer development time. Geoffrey Moore discusses at length the concept of core versus context in the book, Dealing with Darwin: How Great Companies Innovate at Every Phase of Their Evolution. According to Moore:

  • Core is any activity that creates differentiation in the target market resulting in premium prices or increased volume
  • Context is any activity that does not differentiate your company from the customer's viewpoint

Moore further explains, “Core is what companies invest their time and resources in that their competitors do not. Core is what allows a business to make more money and/or more margin, and make people more attracted to a business than to its competitors. Core gives a business bargaining power: it is what customers want and cannot get from anyone else.”

Engineering teams often fall into the trap of investing most of their time and effort into tasks that are critical to the success of the application, but aren’t differentiators. In industry, approximately 90 percent of R&D resources are deployed toward non-differentiating tasks. These features are essentially table stakes: customers expect this functionality, there are consequences if it fails, but it doesn’t set your business apart.

To reallocate your resources toward core tasks, you can implement a few strategies:

  • Standardize—Reduce variability in your processes and systems to reduce cost and risk
  • Modularize—Deconstruct a product into modularized subsystems so that components can be reused.
  • Outsource—Drive processes out of your business entirely to reduce overhead

Because the NI platform is both flexible and scalable, you can implement all three strategies listed above. By standardizing on the NI platform, you can reuse code modules and architectures across multiple projects; customize hardware by choosing the form factor and modules for your application; and outsource development, testing, and sustaining engineering costs.

The more you can move your engineering effort away from context, the more you can reallocate valuable engineering resources toward your innovative IP that sets you apart from your competitors.

Technical support consists of two distinct considerations:

  1. Support needed by the design team from the vendor

For more complex components, vendor support can reduce development efforts and risks to the project. Vendors can provide valuable expertise and support that can save you development time and effort, and can often advise you on design best-practices.

  1. Support that you must provide to your end-customer

In regard to the supportability of your product, the cost of support and RMAs is related to the testing, verification, and documentation that goes into a product before it is shipped. In addition, as designs become outdated (perhaps because the cost of upgrading is too high) access to the right support resources becomes more limited.

Another consideration that impacts supportability is Internet of Things (IoT) compatibility. IoT features such as remote access, system management, and health monitoring have the potential to significantly reduce the cost of field technical support. Innovative features such as predictive maintenance or machine learning can actively prevent system downtime.

Incorporating IoT technology requires additional skillsets in your development and likely requires collaboration with multiple technology vendors that each offer part of the IoT technology stack. NI customers benefit from the partnerships that we have created with IoT technology leaders like Cisco, Intel, and Xilinx, and consortiums like OPC UA and the Industrial Internet Consortium.

As with any design, there are always a few wildcard considerations that can be hard to quantify. Perhaps your company is moving in a new business direction, and your design team is motivated to develop the skills for future use. Or perhaps you have a developer who is passionate about learning a skill that she doesn’t have expertise in today. In these cases, the benefit of designing in-house is still risky, but it could be worth it.

However, maybe a COTS solution has more features than you need today, but it allows you the option to expand your functionality in the future. This might be a good reason to buy a more full-featured COTS option than you might have otherwise considered.

How to Select the Right CPU or SoC for your Embedded Project - Qt

The central processing unit (CPU) or system on a chip (SoC) you choose for an embedded system dictates how well the system will work. I have years of experience building embedded systems and offer tips and those from other experts, on picking the best CPU or SoC.

For more embedded moduleinformation, please contact us. We will provide professional answers.

In this article:

  • When you should select the CPU or SoC for an embedded system
  • Factors to think about in assessing a CPU or SoC
  • Comparison matrix of top SoCs/CPUs for an embedded system

What is an embedded processor?

An embedded processor is a central processing unit built into an embedded system that controls the system's basic functions. Embedded processors are a type of microprocessor and usually have limited functions. Often, they use minimal power.

What’s the difference between an embedded processor and a microcontroller?

Embedded processors come with only the processor in the chip. They require external memory and other external components and peripherals to work. Microcontrollers have everything needed to perform a task—including memory, signal registers, and input/output ports—built into the chip. 

Manufacturers use embedded processors when a processor must use limited power. They use microcontrollers for various products with embedded systems, including smartphones, automotive systems, and advanced medical devices.

What is a system on a chip (SoC)?

A system on a chip, or SoC, brings together all components a computer system needs onto a single computer chip. An SoC includes the CPU and other parts like memory, timers, and communication interfaces.

What’s the difference between a CPU and an SoC?

A CPU, or central processing unit, generally comes with only the processor in the chip. Computer and embedded systems sometimes use multiple CPUs. An SoC is a minicomputer on a chip that does all the computing work while a CPU needs other components to complete.

A CPU always requires parts outside of the CPU—including memory, timers, and other components—to do their work. An SoC is like a microcontroller but is much more sophisticated and powerful.

What is an SoC in an embedded system?

An SoC in an embedded system is a chip that includes all the components that allow the chip to perform a specific function or action for the embedded system. Many embedded systems use SoCs to do their computing work. 

The main elements of an embedded SoC include the processor and other components like memory, cache, timers, and input and output ports. The main advantages are that they use less power and can ultimately be a less expensive solution than a CPU.

SoCs often use much less power than a CPU and its extra components or the multiple CPUs that an embedded system sometimes requires. Embedded manufacturers use SoCs when they need a powerful self-contained processor that still takes up little space.

SoCs have all of the components they need, often making them less expensive than the cost of a CPU and the extra components it requires. Veli-Pekka Heinonen, Qt senior product manager, explains, "Many projects have limits, to get below a certain (cost) threshold. So SoCs have been good at the cost-effectiveness side of things."

A primary disadvantage of choosing an SoC is that manufacturers who use them will have limited flexibility in changing the system. For example, with a CPU and external memory, a manufacturer can decide to change or add to external memory. That's not possible with SoCs. You would need to change the entire SoC if the system needs significant modifications.

Who should select the embedded SoC/CPU?

Since a CPU or SoC is part of the hardware of an embedded system, some people believe hardware designers should choose what to use. But involving software designers in the decision is vital. 

That's because how an embedded system ultimately works, including how any software works, will depend on the CPU or SoC. The embedded system will work well only if the hardware and software blend together.

  • Hardware considerations: Hardware experts will pay close attention to how much power the CPU consumes. They will also care about the overall computing power and how much space the CPU uses. Finally, the cost is a factor.
  • Software considerations: Software designers and experts will focus on how the system’s software will work with the CPU or SoC. They will want their team to be familiar with the CPU architecture and ensure the development tools they use with the CPU. Finally, it’s critical the team can easily test how the software works on the system.

    Qt's Heinonen says, for example, that more and more systems are using ARM-based processors. "So that also then impacts the software." 

When to select the right embedded CPU/SoC

The CPU is the foundation of the embedded system. But you should wait as long as possible to pick one to use. That's because the team will know more about hardware that will work best with the software they’re developing for the system.

You do not want to decide on and purchase a CPU or SoC and then find out that the software your designers have built for the embedded system doesn't work well with it. It’s important to understand what the software requires in terms of memory, power, and performance. Then purchase the best CPU that fits those needs. Learn more about how embedded engineers build an embedded system and develop the software. 

Rob Wood, vice president for hardware and embedded security services at security consultancy NCC Group, explains it's also essential that embedded system designers choose a CPU or SoC "only after you have a solid understanding of your security requirements. The SoC is the foundation of your security. Everything outside of this component cannot be trusted. So, the security properties of your SoC will determine the security of the system as a whole. Updating a design with a new SoC can take years of effort. So, the selection is very important."

How to assess embedded SoCs/CPUs

You'll want to consider many factors when deciding on the right CPU or SoC for your embedded system. You'll, of course, consider overall performance, memory needs, peripheral needs, and costs.

Here are key things to consider when picking a CPU or SoC:

  • Performance: The most important factor, of course, is the CPU's overall performance and speed, which the CPU's or SoC's architecture and chip design determine. Be sure to review the number of instructions the CPU executes per second and the number of operations per clock cycle.

    Assess the CPU or SoC based on the raw computing power your embedded system and its application need to work well. You may want to choose a few options and then run trial simulations with your code.

  • Memory: If you choose a microcontroller or SoC, make sure it has the memory capabilities your software needs. If you opt for a CPU, ensure it can support the memory needs of your software. Read our embedded memory guide to learn more about types of memory in embedded systems and issues to consider when choosing memory for an embedded system.
  • Power draw: Often, great CPU performance means more power consumption. But you can use techniques to decrease the needed power draw or decrease it at certain times. Still, the power the CPU or SoC needs will be critical in your decision. There are good options that offer high performance with low power consumption.

    "With the emphasis on green energy, energy consumption is something that is coming up a bit more often," Heinonen says of assessing CPUs and SoCs.
  • Peripherals: Properly supporting the peripherals your embedded system uses is vital, of course. With SoCs, the peripherals will often be in the chip. That often means more efficient power consumption and better data transfer compared to external peripherals that are external.

    If you're using a CPU and your peripherals are external, make sure it supports their operations efficiently.
  • Architecture: You'll want to understand the architecture of the CPU or SoC. That architecture will affect which operating system you can use, as well as software performance.
  • Operating voltages: In recent years, computer chips have reduced CPU power consumption by reducing the chip's operating voltage. But that may come with changes in performance. You'll want to choose a CPU with an operating voltage that limits power consumption while ensuring great performance.
  • Security: As Wood, from NCC Group, points out, security is vital in choosing a CPU or SoC. The continued evolution of the Internet of Things (IoT) and Artificial Intelligence (AI) in embedded systems only increases security concerns. You'll want to understand the security architecture that's built into the CPU or SoC. Make sure it has the architecture that anticipates and combats the most common forms of attacks.
  • Specialized processing: Some embedded systems use co-processors or special processing units to reach their best performance. Many systems—including mobile phones, for example—need a graphic processing unit. Choose a CPU or SoC that works well with those co-processors or processing units.
  • Cost: The cost of the CPU or SoC will be a key consideration, of course. Be sure to review all the expenses that are part of your choice. That includes costs for development tools, peripherals, and the necessary circuitry and components. Plus, consider if you’ll need to train your staff to work with your selection. You can learn more about essential skills for embedded systems engineers.

CPUs for Specific industries

Specific manufacturers make CPUs that are built for and perform well in embedded systems within certain industries. For example, the automotive industry often uses Qualcomm or Renesas processors. The medical industry often uses NXP equipment.

Comparison of the top embedded SoCs/CPUs

Qt has prepared its embedded product planning and requirements guide to help engineers understand how to approach building an embedded device. The handbook includes a detailed comparison of some of the top SoCs used in embedded systems.

★ is the lowest ranking while ★★★★★ is the highest. 
* SoCs may include additional features that are unexposed by an eval board.

Future Trends in SoCs in Embedded Systems

Most experts believe that SoCs will drive most embedded system processing in the future instead of general-purpose CPUs. Advanced SoCs now integrate memory, a graphics processor, and other important features onto one chip. 

Why you should take your time to pick a CPU or SoC 

Your choice of a CPU or SoC for your embedded system is probably one of the most important decisions you’ll make when building an embedded system. The processor can be one of the most expensive parts of a system, and it must work well with the software. Choosing a CPU that you will end up needing to change later becomes even more expensive. That's because the CPU affects so many other choices you make in building your embedded system.

Embedded development framework vs. build an embedded tech stack

Qt helps you develop embedded systems that work well and you can get into the market quickly and at a low cost. Qt gives developers the special tools that help them build cutting-edge embedded systems. Those tools help developers with a wide range of applications and needs—including everything from creating two-dimensional and three-dimensional graphical interfaces to building systems featuring advanced automation.  With Qt you can have one implementation and cross-deploy from low-end to high-end products, if your product line has both, and something in between as well. 

Use our ROI estimator to estimate what your return on investment will be by migrating to Qt.

The Embedded Product Planning and Requirements Guide

In this guide for IoT and embedded product planning, we examine the most important criteria to consider at the outset, compare a list of the most used technologies, and rate them in easy-to-compare categories.

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