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| On 12, Aug 1998

Darrell Mann, Industrial Fellow
Department of Mechanical Engineering
University of Bath
Bath, BA2 7AY, UK
Phone: +44 (1225) 826465
Fax: +44 (1225) 826928

Much of Edward de Bono’s pioneering study on lateral thinking stemmed from the hole-digging analogy he developed in his very earliest work (‘The Use of Lateral Thinking’, 1967). In the analogy, we are trying to solve a problem, the solution to which is a seam of gold buried at some unknown location in a field.

If the problem we’re trying to solve is ‘similar’ to one we’ve already solved, we are likely to attempt to solve it using what de Bono described as ‘vertical’ or ‘logical thinking. In such a scenario, we have already started digging a hole, we’ve already found some gold in it, and we are expecting to find the solution to our new problem simply by digging – vertically, logically – deeper. Whole industries are built on this very principle. The next automobile to emerge on the market is almost guaranteed to emerge from a hole labeled ‘4-wheeled, internal combustion engine driven vehicle’ for example. The next car tyre from a hole labeled ‘molded rubber, radial wound re-enforcement’. The next driver protection system from one labeled ‘steering-wheel mounted, inflating bag’. And so on, and so on, at each and every level – from the macro to the micro – of whatever problem it is we’re looking at. Each of the products or solutions that emerges will generally have been obtained by digging an existing hole a little deeper.

Unfortunately, once we’ve started digging a hole, it doesn’t take long for our competitors to find us. In a mature industry like the automobile one, we’ve probably dug a quarry-sized hole, all the other manufacturers are in there with us, and we’re all desperately scratching around for some nugget or other which will discriminate our product from everyone else’s for a year or two.

Unfortunately also, we all suffer from psychological inertia (PI). In the context of the hole-digging analogy, this is the thing that tells us to stay in the hole we’ve been digging. It is the thing that tells us that if we just keep on digging a bit deeper, we’re bound to eventually come across the solution we’re looking for. It is the thing that tells us ‘look how much time and energy we’ve expended digging this hole; how could we possibly let it go to waste?’ It is the thing that gives us a quite potent image of industries digging deeper and deeper holes that they are progressively less likely to be able to get out of.

De Bono used the term ‘lateral thinking’ to denote a different kind of thinking to the vertical/logical variant. Lateral thinking is the thinking that prompts us to set about looking somewhere else in the field in search of a better solution. Lateral thinking is the thing which got us out of a hole labeled ‘horse-drawn carriage’ into our current ‘4-wheeled, internal combustion engine driven’ one. It will also be the thing that gets us into the next hole, whatever that might turn out to be.

Of course, the difficult part here is knowing where to dig our new hole. In the past, we probably did it to a large extent by accident or hunch or guesswork. Today, we can usually no longer afford either the time or money to embark on this type of random digging exercise. Economic and competitive necessities demand that if we’re going to dig a new hole, we’d better have a pretty good idea where we’re going to start before we pick up a shovel.

De Bono recommends a number of techniques to help locate worthwhile places to start digging new holes – for example PMI or ‘Po’ or word-association (‘pick a random word from a dictionary…’) – some more useful than others. None however appear to be as powerful as the opportunities that have emerged through the TRIZ methodology.

In the context of the finding the right place to begin digging a new hole analogy, there is probably no single technique in existence more powerful than the 40 Inventive Principles idea. For here is a technique which says that actually there are only very few places where we might profitably dig a new hole. And, further, if we also use the Contradiction Matrix, we find that for any given problem, the list of places to look further reduces to only three or four out of the original 40.

Of course, this is a naïve view. Naïve in that it assumes a) we are attempting to solve the right problem and b) the Contradiction Matrix is infallible. With respect to this second issue, despite the very large number of case studies used to derive the Matrix, this author has discovered too many instances where a ‘better solution’ has arisen through use of Inventive Principles other than those recommended by TRIZ for a given pair of contradicting design parameters. Too many, certainly, to permit reliance on the recommendations of the Matrix alone.

The first of the naive assumptions, however, is the more serious. TRIZ is an undoubtedly powerful problem solving method. So much so that if we set out to find gold in a field, we can be pretty confident we’re going to find it. But, if we actually wanted something other than gold, then being able to locate gold is actually of little use to us. Perhaps a good illustration of this is the air-bag problem solving exercise reported in earlier issues of TRIZ Journal. The exercise was as good as any in demonstrating how TRIZ was able to locate an awful lot of usually good solutions to the ‘better air-bag’ question. An awful lot of air-bag shaped gold, but unfortunately not an awful lot of ‘protect passengers in all accidents’ or, as one letter writer later observed, ‘stop drivers taking increased risks as a result of feeling safer’ shaped diamonds.

Some applied innovation researchers have suggested that problem definition – determining what it is we’re digging for – should be given rather more of our attention than the then comparatively simple tasks of location finding and hole digging. Unfortunately, another depressing human psychological trait – our apparent need to be seen to be ‘getting on with the job’, to show some shovel-wielding sweat – often means we don’t give problem definition nearly enough of the attention it in fact merits. Psychological Inertia, however, also comes into the problem definition equation. Psychological inertia is the thing in this context which says to us ‘I’ve been digging for gold, I’m good at it, people have always bought the gold I find, I’m going to keep right on doing it’. It’s the thing which tells us not to even think about the fact that people might one day decide what they actually want is something other than gold.

So, what’s this hole-digging analogy stuff all about anyway? What has it got to do with Psychological Inertia? And what is there we can usefully learn from it? I submit three thoughts for your consideration:-

Effective gold seam location requires a map. The 40 Inventive Principles of TRIZ are probably the best mapping tools available anywhere. Awareness that there are 40 principles and that any might be useful to solve a problem gives us 40 extremely effective means of defeating PI.

The image of seeing myself stuck at the bottom of a mile-deep, vertically sided quarry is the very best way I know of telling myself perhaps, maybe I’ve been caught out by the PI thing again, and that perhaps, maybe I’d better start thinking about finding myself a better hole to dig. There is always a better way.

Not only does Psychological Inertia try and prevent us from getting out of the holes we dig, it also tells us to assume that what we started out digging for remains constant. It often doesn’t, and we therefore need to be aware of both problem definition and problem solution aspects of the PI problem.

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1998, University of Bath, all rights reserved.