There are three distinct operating modes in the Widget firmware.  This section describes how we go about ensuring that this firmware is working as well as it must be in order to be part of our communications system.

Here is a quick summary of where we are today:

    ... now let us learn what this means:

Getting to "Flight-ready" status

We establish confidence in our Widget firmware through verification using 1st and 2nd implementation of all modes and 1st and 2nd implementation of the IHU control of
these modes.  Only after achieving these implementations of Widget modes and IHU control of these modes and incorporating the feedback of what we've learned in each implementation attempt do we consider the firmware modes "Flight-ready".

Here's what I mean by 1st and 2nd implementation:

As the designer of the system, I accomplish the first implementation. My implementation effort serves to prove that I understand enough of the issues affecting implementation, that I can confidently describe (through documentation) how to implement, and that my view of these issues is complete enough that my implementation can be successful. (Mine worked as intended.)

Someone other than the designer (other than myself) accomplishes a 2nd implementation. This serves as proof that all information needed to succeed in implementation has been communicated and that at least one alternative approach to implementation can achieve functionality. (Someone else has made one work using the documentation and tools prescribed and has fed-back any issues found in the documentation and/or operation of the Widget in this mode!)

by Stephen, KZ0Q