April 2009

Products that offer integration at the factory

In a perfect world, there are no uncertainties. We completely understand and account for all variability.

Our real life experiences and expectations are different. Integrating systems, even those designed to work together, can pose some unique challenges during the installation process.

To understand some of the systemic issues related to integration, we need to look at the structure of the various components that integrate into a system.

Consider the interconnectivity between the hardware components and a user application in a "typical system." It is clear that if different vendors supply various components of the system, there is a potential failure point at each interface. Integrators can minimize this effect three ways:

  1. Industry standards for bus architecture
  2. Industry standards for hardware design and software interoperability
  3. System level integration


A typical product development that spans both hardware and software functionality follows the pattern of a "zipper," the hardware and software pieces are not physically mated together until both pieces are fairly well progressed in their development cycle.

Frequent communication between the two groups during their respective development process will cause the meshing process to go smoothly. However, it is important to understand the validation goal at this level is gearing towards functional compatibility between the hardware and software.

An effective way to improve proper meshing is to rely on a standard hardware specification for device pin-out and triggers and a common software specification for the driver. An example of an industry standard that defines both a hardware and software specification is the PXI standards (www.pxisa.org).


Another component to the validation process is ensuring interoperability-to make sure the hardware and software combination can coexist amicably in the framework of other products that are likely to be under the user's platform.

This is where the level of uncertainty rises dramatically. For example, let us assume the supplier's portfolio of platform products include a small catalog of 10 products that can be integrated together. Simple permutation tells us these 10 products can go together in over 3 million ways. It is physically impossible to test out every single combination of hardware and software from a typical catalog of products.

So the Validation and Verification (V&V) process involves educated estimates on the most likely causes of failures and tests for these scenarios. The V&V testing validates interoperability under these scenarios using the versions of hardware and software tested.

However, by the time the product integrates into a customer system, other combinations may come out, or the versions of tested combinations may have changed.

The V&V testing is unlikely to be the catch all incompatibilities. It is primarily a risk mitigation tool.

High quality of the V&V testing and tight control on the temporal development of products can reduce the integration risks for a customer system, but this risk will never completely go away.


Source: This analysis of integration issues and the concept hardware and software interoperability "zipper" comes to InTech from National Instruments (www.ni.com).