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Principle 3 Deep Dive

Principle 3 Deep Dive

| On 15, Mar 2018

Darrell Mann

A couple of months ago we did an analysis on the case studies we’ve been involved with during the past few years. Projects that have either been our own, or ones where a client has asked us to participate in the solution generation activities. When it comes to contradictions and contradiction-solving, it seems that we have consistently had our biggest successes coming through solutions generated with the assistance of Inventive Principle 3, Local Quality.

I don’t think this was a particularly big surprise to me, since Principle 3 is one of my standard ‘go-to’ solution strategies, and has been so almost since I even knew TRIZ existed. What has been surprising is the reaction we often receive from others when we say these words. Principle 3, the replies usually go, isn’t that one of the really abstract Principles? From which I interpret, ‘difficult to use’. I can see that this might be the case. It is generic. To me that’s where a lot of its power comes from. But then again, if you’re a person that doesn’t have the opportunity to use TRIZ and the Inventive Principles every day, then perhaps ‘abstract’ is a problem. I thought I’d take the opportunity in this article to dig a little bit deeper into why I think Local Quality is one of the most powerful of the Inventive Principles.

To start the story, it seems relevant to head back a few years to an article we produced for the December 2004 issue of the ezine (Reference 1). The article was an attempt to help newcomers get the best out of all 40 of the Principles. It did so by making the point that each of the Principles comes in two parts: a connection part and a direction part – Figure 1:


Figure 1: Connection:Direction Solution Generation Strategy

What this means is that, when we’re looking to use the Principles as a provocation to move us away from an existing solution to a productive new one, it works in two stages: the first stage requires us to make a connection between the entity we’re trying to improve and the Principle. The second stage then requires us to use the direction part of the instruction to alter the part of the entity we connected to. For Principle 3, the connection and direction elements are reproduced from Reference 1 here:

3, Local Quality A uniform/’homogenous’ entity

Something uniform around the system

Different parts of a system

Make it non-uniform/non-homogenous



Locally optimize each

Different (possibly opposite) functions

Let’s look at a couple of examples to see how the SI team will look to use this Connection:Direction method to generate large numbers of ideas. The main point at this stage being an emphasis on ‘large numbers’. In any creative process it is always important to separate the job of generating ideas from the (subsequent) job of evaluating those ideas. The usual rule when we’re in ‘generation’ mode is that we should be looking to make at least a dozen connection:direction provocations for each of the Inventive Principles we use. If we’re being tough on ourselves – something we’re very likely to do when it comes to Principle 3 – the rule is twenty.

First up, let’s examine a simple product-based example. The fork. In theory a near universal artifact that has had hundreds of years’ worth of evolution. And yet, when we start the process of thinking about fork improvement ideas using Local Quality, and we look to connect aspects of the fork that are ‘uniform’ or ‘homogenous’ we can quickly find there are many:

Figure 2: Fork ‘Homogeneities’

There’s 12 evolution opportunities already, but still not 20. Now let’s zoom in and look at the micro-detail and see if there are more homogeneities:

  • Young’s modulus – same everywhere
  • Poisson’s Ratio – same everywhere
  • Surface energy (hydrophobic/hydrophilic) – same everywhere
  • Surface hardness – same everywhere
  • Coefficient of thermal expansion – same everywhere
  • Density – same everywhere
  • Colour – same everywhere
  • Friction coefficient – same everywhere
  • Stiffness – same everywhere
  • Strain rate – same everywhere

…and there’s another 10, without getting in to any of the more detailed material properties we might care to look at. Rather than do that, let’s now zoom-out and look for homogeneities at the ‘meta’ level:

  • All forks in a cutlery set are the same
  • All have the same profile to (supposedly) achieve efficient stacking
  • All carry the same makers mark
  • All designed for the same ‘average’ human hand
  • All designed for the same ‘average’ human mouth
  • All designed for the same ‘average’ washing process

And now we’re already well past our ‘ambitious’ target of twenty. We could go on, but hopefully the point is made. Actually, two points: the first being that all I’ve done here is use the 9-Windows viewing tool – actually just three of the nine windows – to look for connections from the sub-system, system and super-system perspectives, and in so doing have uncovered homogeneities that might otherwise have remained invisible.

Secondly, resulting from this ‘invisibility’ are the assumptions the fork designer made when he or she was drafting their beautiful fork design. Or rather what they very likely allowed their CAD system to fill in for them. It’s easy to allow the CAD to default to constant everything. Make the thickness the same everywhere – great for the designer, because it’s now saved them the tedious job of having to specify all three dimensions separately; make all of the tines have the same parallel sides – another drafting time saver. But every time the designer allowed the CAD system to save them a few precious seconds, the eventual product took another turn for the worse. Now, in fairness to the designer (and the CAD system software engineers), a lot of the assumptions built into the CAD software have been made to assist in the mass-manufacture of the artifact. If all of the tine walls are parallel, that’s great because now we can manufacture the forks using a really simple stamping press. 9000 forks a minute, job done. Except, of course, we’ve now allowed the manufacturers convenience to take precedence over what might have benefited the customer. The customer, of course, also (implicitly) likes the idea of a low-cost fork, but then again, we’re still allowing ourselves to fall into the trap of assuming things have to be the way they always have been. So, ‘of course’ the material is homogenous – with the same hardness and strength everywhere, and with the same level of hydrophobicity, because ‘that’s the way the sheet of steel arrived’. Spot the assumption? Who says we have to start with a sheet of steel? Now we have 3D printing, that assumption becomes irrelevant. Now we can just as easily print a ‘meta-material’ with different properties at different points in the design as we could the standard homogenous product. Nothing has to be ‘homogenous’ any more… and that’s why Principle 3 offers up so many opportunities to make our invisible assumptions very visible indeed.

Let’s see if the same idea works in the far less tangible space of a ‘people’ problem:

Figure 3: Pharmacy Homogeneities?

At first sight, it doesn’t look like there are too many ‘homogeneities’ in this picture. Quite the opposite in fact since the overall impression is perhaps one of ‘random clutter’. However, let’s see if we can find our ‘twenty’…

(In no particular order)

  • All of the prescriptions are handed out in a standard bag
  • All pharmacies have the same basic layout (serving counter adjacent to another, higher, counter the customer can’t see behind (why?)
  • Prescription drugs are dispensed ‘unseen’ in a room behind the counter
  • All ‘customers’ are assumed to be the same: ‘ill’
  • Customers assume all ‘pharmacists’ are the same
  • The pharmacist always ‘controls’ the transaction (they know; we don’t)
  • All products on offer are equally indiscreet
  • All customer spaces are equally indiscreet (no privacy)
  • All products exist to ‘cure’ or ‘remove’ symptoms
  • All of the branded products come in the same packaging (understandable from a branding perspective, but not so great from an overall visual display perspective)
  • All the store aisles are parallel and a standard width
  • All the most popular products are found at eye/hand level
  • The ‘pharmacy’ is always at the back of the store
  • All parts of the story are equally lit, with the same colour lighting
  • The temperature is the same everywhere in the store
  • Each hour of the day is the ‘same’
  • Each day of the week is the ‘same’
  • Each day of the year is the same (no apparent accounting for seasonality of many medical conditions)
  • The pharmacist goes to lunch the same time as all the patients/customers coming in to the store
  • Prescription prices are all the same

As soon as we have made our ‘homogenous’ connection, the direction part becomes ‘obvious’ – make it ‘non-homogenous’. Again, this is intended to be interpreted in a myriad number of different ways, but ultimately, all of them are about overcoming the ‘time-saving’ assumptions we – and the designers of pharmacies or forks – have unwittingly made. Maybe it’s easier for the outsider to see them (and hence why we have used Principle 3 so often within the SI team), but every time TRIZ/SI tells us to solve a contradiction using ‘Local Quality’, it’s try to tell us that, somewhere – at least twenty places! – we took a wrong short-cut, and now’s the time to correct it.


  1. Systematic Innovation E-Zine, ‘Connections & Directions Towards The More Ideal System’, Issue 33, December 2004.



  1. Kevin J. Dutcher .

    That’s a great list of characteristics. Has somebody tried to codify characteristics for different types of objects, i.e. mechanical, electrical, chemical, SW, etc.