This week at OR, we’ve been discussing “scenario planning,” a method for visualizing alternatives which allows planners to perform risk management type activities. Wade (2014) says scenario planning asks two fundamental questions “What could the landscapes look like?” and “What trends will have an impact (on us) and how will they develop?”. In Wade’s model, two or more trends are considered, using an “either … or …” framework for each then pairing the various endpoints in a matrix. For example, a researcher might decide that oil price and electrical stability are the two factors that will impact our future plans. The researcher would set two extremes for the “oil price,” say ‘higher than now’ and ‘lower than now,’ and two extremes for the stability, say ‘cheap and plentiful’ and ‘expensive and scarce.’ By combining those four extremes, the researcher could define a set of four scenarios which would allow for planning.
It turns out that much of what’s written about scenario planning is based on financial forecasts. One notable failure of the model involved the Monitor Group, which ironically performed scenario planning for other companies. The problem they faced was akin to a mechanic getting into an accident because his vehicle had faulty brakes. (Hutchinson, 2012) Monitor Group got into trouble when they began to experience negative cash flow. They trimmed the employees by 20% and assumed they would weather the coming storm until the market picked back up. (Cheng, n/d)
It didn’t. They didn’t.
Victor Cheng (ibid) opined that Monitor fell because they spent too much time in denial that their models were not working. Desperate for cash, they contracted with Libyan Dictator Moammar Gadhafi in an attempt to improve his image which ironically hurt theirs. He suggested that Monitor should have “protected its reputation” to be able to borrow during their downturn. They should have monitored (no pun intended) their Pride and Ego which told them they couldn’t be having these problems since they solve them for others. Hutchinson (ibid) also suggested that this is a common problem within organizations, where collectively held beliefs can be spectacularly wrong. And finally Cheng warns, a “strategy” is only as good as the paper it’s written on. Execution of the strategy is hard and needs to be monitored closely to prevent ending up alone and in the weeds.
So why am I writing about this you ask? To me, this scenario planning is at the core of software testing. How do we know which scenarios to test? How do we find interesting combinations of actions? How do we validate that complex behaviors are working in a way that makes sense?
Many of the same tools can be used to define the scenarios for testing the autonomous vehicles. Delphi, affinity grouping, brainstorming are all well known ways of collecting requirements. Each can be used to help define scenarios we would be interested in. Once we have the many thousands of ideas for what a vehicle must do in a specific situation, we can start grouping them together by process or mechanical grouping to find overlaps.
I recently began a project to define the tests that were necessary for a small cash register program I was brought in to test. After playing with the application for a week, I started writing test cases. I came up with nearly 1400 of them before I got to talk to the development team. I showed them my list and told them that I would need their help to prioritize the list since we obviously would not be able to test them all. Their eyes widened. Then they asked me a question that shocked both them and me. How much of this have you already tested while working this week?
I set down my sheet and said, “Before I defined these tests, I felt I had a fairly good grasp of your product. I would have said I was working at about 80% coverage. Now, looking at all these paths, I might have been up to about 10% coverage.”
I believe the automotive testers such as Google have only begun to scratch the surface (no pun intended) of their required testing, even with all the miles they have under their belts.
Next post, we’ll start looking at some of those possible scenarios and we’ll start trying to define a priority for them as well…
Cheng, V. (n/d). Monitor group bankruptcy-the downfall. Retrieved from http://www.caseinterview.com/monitor-group-bankruptcy
Hutchinson, A. (November 13, 2012), Monitor group: a failure of scenario planning. Retrieved from http://spendmatters.com/2012/11/13/monitor-group-a-failure-of-scenario-planning/
Roxburgh, C. (November 2009). The use and abuse of scenarios. Retrieved from http://www.mckinsey.com/insights/strategy/the_use_and_abuse_of_scenarios
Wade, W. (May 21, 2014) “Scenario planning” – thinking differently about future innovation (and real-world applications). Retrieved from http://e.globis.jp/article/000363.html