Archive for September, 2007

Building Reliable Systems

Wednesday, September 19th, 2007 Michael Barr

I’m writing this live from the Embedded Systems Conference in Boston, while participating in a birds of a feather discussion moderated by Jack Ganssle. The subject of the session is Building Reliable Systems.

The discussion here amongst perhaps 80 engineers (about 75% electrical engineers by education) initially focused on resources and schedules and the inevitability of bugs, but has now turned to what seems to a more productive thread: specific processes and tools that produce higher reliability.

One gentleman, had a great way of summarizing what needs to be done at a high level:

* Prioritization
* Process
* Metrics

In this view, Prioritization is an input to the Process. That is, prioritization of features relative to one another–as well as the accurate definition of properties such as quality and reliability. These are to be provided by the customer or from engineering management. The Process used for design and development and testing are then guided by these input parameters. Metrics are an output of such a Process, if you strive to generate them. Metrics include the schedule time it took to complete specific feature implementations, as well as bug rates.

On the specific point of process and tools, we’ve discovered that just a few companies represented in the room are using code coverage tools and test-driven development, though most appear to agree these might be helpful in raising reliability.

My bottom line fear: One of the products designed by someone in the room with me right now will kill or maim eventually!

Embedded Industry Survey Results

Sunday, September 9th, 2007 Michael Barr

I was quoted (mostly accurately :-) over at, in an analysis of the results of the 2007 survey of embedded system designers. There are some interesting year-on-year trends, including an increase in the use of C vs. C++ and a decrease in the use of both commercial and open-source operating systems such as VxWorks and Linux.