Industrial automation systems are performing more tasks and doing so more quickly

Beyond this, the modular COM Express approach allows users the flexibility to deliver application-specific performance and power at an appropriate price level (Figure 1). For instance, a quad core i7-based processor module can be used on a specific carrier board for a high-value, high-criticality, high-performance application – while the same carrier board, with the same features and I/O functionality, can be deployed for a lower value, less critical, less demanding application with a lower-performance VIA Nano processor-based COM Express module; this results in lower development cost and faster time to market.

price/performance balance.
The advantage of this level of modularity extends well beyond the initial deployment, however. In the longer term, upgrading the level of performance is simply a matter of replacing the processor module – not the entire subassembly. This saves money, and minimizes unforeseen impact on the way in which the module as a whole interacts with its surroundings.

In the locomotive example mentioned, the COM Express processor module can be upgraded without affecting the connection to the engine I/O residing on the carrier board – reducing costly and time-consuming recertification and testing. The modularity of COM Express gives a whole new meaning to “technology insertion.”

refer to:http://industrial-embedded.com/articles/rugged-increasingly-connected-world/