Systems & Software Talk 

A long long very long time ago back when I was knee-high to a grasshopper and Inter-Gore-Net was not even a dream, unbeknownst to me at the time I was engaged in Verification & Validation (V&V). Two of my sisters had just received battery-powered electric mixers as Christmas gifts. These mixers were of course kid size and in today’s world would be considered hazardous (choking, flesh wounding, etc.). As we will see later, these represented a different kind of hazard as well.

Magnets and electrical things fascinated me. I with a butter knife had already learned why electrical outlets were called outlets rather than butter knife holders or inlets. I was advanced for age six! (reallly now :) ) When I looked at these mixers, I envisioned magnets. You see we didn’t have refrigerator magnets in those days because not many people had refrigerators. With our icebox, why would we need refrigerator magnets? Is not necessity the mother of invention? It all makes sense to me now. Refrigerators were built to hold refrigerator magnets, and - some would argue beer.

As with so many other IT terms, V&V can be confusing. Why doesn’t someone design and develop a handheld device that will spit out the definition of an IT term or acronym when one asks it? After all this is IT. Are not there similar devices for language translation and spelling?

I wish to confuse things a bit more! I will now refer to Verification as VR and Validation as VL.

VR consists of methods – some formal, to prove in our world that what is being specified, designed, and built; is in fact being specified, designed, and built properly.

VL consists of methods – some formal, to prove in our world that what was specified, designed, and built; was in fact specified, designed, and built properly. The as-built inspections folks also known as the blackbox, functional/regression folks of the world generally descend upon the thingy with the intent to prove that the thingy was built properly and show where the thingy might not have been built properly.

Here is an example that draws contrast between VR and VL.

NOTE! Your local adaptation of these V&V concepts may vary.
One example of an unlimited number of examples:
Let us say you have a web app that is supposed to show the local time on every page of the app. Some verification activities one might expect are:

1. Use a requirement traceability process to track the requirement through documents to the code intended to provide the feature, and/or
2. A code walk-through where one of the walk-through items involves checking to see that the developer addressed the time item – and hopefully if previously developed and put in a library, it was referenced/reused rather than the developer writing yet another time display function.
3. Can be traced to tests – if the tests have been developed yet (see below)
   … just to name a few verification methods of many.

Some validation activities one might expect are:
** Testing to prove the time:

1. Appears in the correct place
2. Is local time,
3. Is formatted properly
4. Addresses local preferences (month, day, year, etc.)
5. Is refreshed properly,
6. Doesn’t occlude other items on a page,
7. Works with specified/supported browsers at specified text sizes and resolutions,

… and so on.

You are wondering about the great battery-powered electric mixer incident of the early 1950s? Ah yes. After I disassembled these, I had hours of sheer pleasure with the magnets, learning about attract and repel. That all came to an end when my sisters discovered that their reassembled mixers sans the magnets failed to function properly. Their VR showed where the thingy did not work since it was no longer an as-built thingy but was an as-modified thingy. My own earlier VL discovered that the thingy had been built properly. that is until I began my VL. My sisters then proceeded to teach me that sometimes people could get very angry when a defect is discovered. These people can also get downright violent and smack one over the head with the modified thingy. I now know why some toys are considered hazardous. Today I do have a refrigerator and I buy refrigerator magnets as opposed to disassembling any power tools I may own. I have not been whacked over the head since.