Unravelling the VW defeat device scandal

What went wrong at Volkswagen? How did VW brazenly, and for so long, cheat on emissions from their small diesel engines? Who all conspired to make it so?

How did VW implement the defeat device which turned on exhaust filtering during testing and turned it off during normal driving, thereby delivering better fuel efficiency?

I have been responsible for developing products for global markets and for transferring a product made for one country or region into another country or region.

I have been responsible for the quality processes used for product development, for product manufacturing and for product in the market.

So, when I look at the VW deception, I wonder how it came to be.

I have managed quality in the development of computer-controlled equipment in the medical device industry. I know from the literature that the major steps in testing software are the same in the automobile industry.

So, when I look at the VW deception, I marvel at how callous so many at VW were.

To explain that statement, I must first describe the product development process.

Product development begins with marketing executives defining "product requirements".

Requirements are broad. For a car, requirements will include the number of passengers, engine capacity, type and grade of fuel, front or rear wheel drive, fuel economy, automatic/manual, target markets (countries), warranty period, cost, etc.

The design team converts the product requirements into "product specifications."

Product specifications are generally expressed in numbers, for example, "miles per gallon" and "maximum emission".

Product specifications also include choice of technology, for example whether the speedometer will be mechanical or digital, and whether the exhaust emission system will require regular top-up of chemicals, etc.

The marketing team must approve the product specifications before the design team proceeds to the next step, which is project planning.

One key step in project planning is to identify the procedures which will be used to control the development process. One of the many purposes of this step is to provide assurance that the eventual product can be tested and confirmed to meet all regulations in all the countries in which the product will be sold.

Regulatory requirements vary between countries. Designers and marketers exploit differences in order to be price-competitive or to claim features which competitor's products do not offer.

For instance, the emission limits in Europe are more lenient than in California. Similar cars designed to "just meet" regulations in California and in Europe may differ much in cost.

For computer software - which is what the defeat device is - the development and testing processes are governed by software development procedures and quality professionals who specialise in the review and testing of software.

For computer software, conformance to requirements - which includes compliance to regulations, requires "passing" two stages of review by independent reviewers.

The first stage, called "verification," calls for review of documents.

The quality team looks at each piece of software and confirms a positive answer to the question "were the correct processes and procedures used to develop this software?"

Items inspected during verification include specifications and test cases (see below). The quality team checks whether the test cases adequately address all the product specifications.

After the quality team certifies that the software has "passed verification", the automobile with the software is subjected to validation.

The testing team validates the software by running the test cases and confirming the results conform to the requirements.

For the defeat device, the test case might require as "input" movement of the steering wheel, and require as "output" inactivation of the exhaust filtering system.

The quality team reviews the validation results and, if appropriate, approves it. This is the final approval of the design.

To unravel the VW deception, investigators could look into the file of "test cases". The defeat device test case will indicate the conditions (e.g. steering wheel movement) under which a tester determined the exhaust filtering was turned off.

Every test case document includes a history of development. The history answers the questions "Who created the case? Who approved it? Who made changes to it?"

A basic quality requirement is that every test case must include links which enable an investigator to trace it back to the requirements.

When first challenged about the emissions, VW went into denial. VW even challenged the results of independent tests in Europe and in the USA.

Did VW even bother to check its test data? Does VW's internal investigation process work? Does VW take customer feedback seriously?

I marvel at how callous so many at VW were. The callousness cuts across the entire VW organisation.

I drive a 2013 VW Jetta, which I think is the best car I have ever driven. Sadly, I now wonder what else VW cheated on and what else VW is hiding.– October 15, 2015.

* This is the personal opinion of the writer or publication and does not necessarily represent the views of The Malaysian Insider.