Benefits of COM-based SBCs: A business perspective

Increased flexibility, upgradeability, and efficiency make the business case for COM-based rather than traditional SBCs

3Traditional SBCs offer quick and convenient solutions to many embedded computing applications, but carry the significant burden of a relatively short lifetime. COM-based SBCs eliminate most EOL problems, but may come with a higher sticker price. When looked at from a total cost of ownership point of view, however, a COM-based SBC is on par with a traditional SBC, while offering improvements in operational efficiency of a user’s business as well as product reliability. This first part of a two-part series discusses the operational and functional benefits of COM-based SBCs. For part two in our Fall issue, Jonathan will introduce an open industry standard for COM-based SBCs utilizing stackable I/O.

With technology quickly becoming obsolete, industries that need long lifecycle products can find it difficult to choose an SBC to last them the next 10 years or more. Computer-On-Module (COM)-based SBCs have advantages over traditional SBCs that can relieve the refresh pressures of applications with long lifetimes. A COM-based SBC consists of two parts: the COM module, which contains a relatively short lifecycle processor circuitry (five to seven years), and the baseboard, consisting of I/O and connector components that usually offer far longer lifetimes (easily 20 or more years) (Figure 1). When the processor chipset becomes obsolete, the COM module containing it can be swapped out for a new one with the exact same mechanical format and virtually identical features (except perhaps for processor performance and power consumption). This enables COM-based SBC vendors to offer longer lifetimes for their products and easily offer multiple performance levels by combining different COMs with the same baseboard. These benefits of increased longevity and performance scalability make COM-based SBCs attractive to both SBC vendors and users, and balance the upfront cost difference over regular SBCs.

Figure 1: A COM-based SBC consists of a standard form factor processor module mounted on a baseboard containing I/O circuitry, a power supply, and connectors. The product typically is the same size as the COM module.
(Click graphic to zoom by 1.9x)

Advantages offset the costs of COM-based SBCs

A common perceived disadvantage when comparing a COM-based SBC with a traditional SBC is its purchase price. A COM-based SBC may have a higher unit price than an equivalent traditional SBC due to the fact that it consists of two PCB assemblies and utilizes relatively expensive, high-speed connectors to interface between them.

The impact of these additional costs on the purchase price may be offset by a supplier who correctly observes that since the development costs associated with the COM-based SBC are significantly reduced (due to the use of off-the-shelf COM modules), the per-unit amortization of those development costs over the lifetime of the product is also lower. Therefore, a supplier can accept a lower gross margin on the product while still maintaining the same net contribution to the company’s operating margin. This brings the price of a COM-based SBC more closely in line with a traditional SBC.

However, even where a COM-based SBC’s purchase price is higher than a comparable SBC, a COM-based SBC offers the customer a lower total cost of ownership due to increased lifecycle of the SBC, which results in greater operational efficiency in production, management, and support. In addition, the impact to the customer’s business is significantly reduced when the time comes to find a replacement product due to obsolescence.

Exchanging the old for the new

The efforts associated with replacing an obsolete SBC can be significant and affect all parts of a customer’s organization. The costs associated with these efforts are difficult to quantify monetarily, but they have a significant impact on a customer’s organization from end-to-end. The related activities may include:

  • Research and evaluation of replacement products
  • Design-in of the selected replacement board, including:
  • – Mechanical design changes

    – Cabling changes

    – Software changes

    – Documentation changes

  • Qualification processes, such as:
  • – Temperature testing

    – Shock and vibration testing – Compliance testing

    – FDA approval

    – Field testing

  • Supplier qualification, relationship establishment, and purchasing negotiations
  • Inventory management of both old and new SBCs, including the complexity of planning the transition from old to new boards, as well as the need to maintain warranty and repair reserves of both models
  • Sales and marketing department updates of their product literature and sales strategies in response to the changes in features or cost of the replacement product
  • Long-term field support of the product in multiple configurations, requiring maintenance of multiple sets of documentation, additional training, and multiple repair inventories

When amortized over the expected lifetime of the SBC, these changeover costs can add significantly to the total cost of ownership of the product. A company that sells equipment at a rate of 200 units per year (a common sales volume for small form factor SBC customers) and is forced to replace an SBC after a typical product lifetime of 5 years (1,000 units) would experience a per-unit cost addition of $100, amounting to a total replacement cost of $100,000. This figure does not include the effect of reduced efficiency in the customer’s organization due to having attention directed away from business development and toward product lifecycle management.

COMs ease transitions in long-lifecycle industries

A typical scenario is this: An equipment manufacturer has been using one vendor’s SBC for control equipment in a commuter railway application. Railway customers typically maintain their products for as long as 20 years. When the vendor’s SBC reaches End Of Life (EOL), which generally happens about every 5 years, the equipment manufacturer is tasked with selecting a replacement product that fits their existing mechanical, electronic, and software platform as closely as possible.

Unfortunately, no two SBCs are exactly alike, meaning that the customer is forced to make a variety of alterations for any replacement product, such as changing its mechanical design, changing its cables, modifying its software to accommodate new chipsets, and selecting additional I/O boards to make up for any functional shortfalls. Once the new product is finally in place, the customer is safe – until the next EOL event. Furthermore, the qualification and phase-in process may take six months to a year, which subtracts from the remaining lifetime of the replacement product and brings the next EOL event that much closer.

Upgrades made easy

Switching to a COM-based SBC makes it much easier to offer a long-life product while reducing the cost of any required changeover. When a COM module reaches EOL, the customer can select a replacement COM that fits the exact same footprint and connectors on the baseboard and contains a virtually identical feature set. At the same time, the overall system design remains the same. This means that the design-in process is dramatically simplified and reduced to primarily software compatibility testing. Replacement costs are also far lower and far less disruptive to business activities.

Users of COM-based SBCs also accrue additional benefits. If the need arises for greater computing power due to an increased load from new software or performance requirements, the COM can be easily be replaced with another one offering higher performance without requiring any changes to the physical design of the system (Figure 2). Also, most COM-based SBCs offer conduction cooling by means of a heat spreader that contacts the system enclosure wall. This means that the removal of heat from electronics is more efficient, leading to cooler internal temperatures and greater reliability of the entire system.

Figure 2: The Magellan SBC from Diamond Systems utilizes a COM Express module as the processing engine. The user has a choice of multiple processors in the same form factor with the same I/O features.
(Click graphic to zoom by 1.9x)

Increased efficiency with COM-based SBCs

Although a COM-based SBC may carry a sticker price higher than a traditional SBC with the same processor, performance level, and features, in the long run the efficiency and flexibility available with a COM-based SBC more than make up the difference. In addition, the impact of any technology refresh cycle is reduced, enabling customers to avoid sacrificing valuable resources maintaining existing products and instead focus on new business and product development.

Jonathan Miller is Founder and President of Diamond Systems Corp. Jonathan is the company’s CTO, CEO, and strategic visionary. He holds a B.S. in Computer Science from the Massachusetts Institute of Technology.

Diamond Systems Corp.