Have you ever walked into a dining room with several pictures and seen that one picture that is not hanging parallel to the floor? If you’re a recovering engineer like me, you feel an overwhelming urge to correct the problem. You just can’t be comfortable until the frame is in alignment… unless you find your molding or floor/ceiling are not parallel. Then you have bigger problems!
Why does a slight misalignment (maybe just a couple degrees off bubble) set off instant and loud alarm bells in your brain? It’s because the human brain is very sensitive to two things:
- Discontinuity (especially non-monotonic functions)
I was having a lively discussion the other day with a director of pricing at a Fortune 500 distributor. We were talking about how this affects product pricing. For example, when you have a catalogue with millions of products, it can be very challenging to keep pricing consistent. Consider the figure to the right. The orange dots could be product offerings for electric motors, graphed by the price vs. a performance attribute, such as horsepower. We expect price to increase with performance. But what happens when you find the blue or green dots? The brain says “that’s not right!”
Now, there may be legitimate reasons for the negative or positive arbitrage. Maybe there is a sale? Maybe there is an economy of scale on selling that particular model? However, that brings us to the next challenge, pricing functions that are not monotonically increasing (i.e. they have a negative slope for at least one product model). This is a problem, because this is difficult for even economies of scale to overcome. And, the customer does not like it, because it makes the vendor look as if their pricing is capricious, which causes distrust.
Discontinuity in Product Costing
This happens in costing too. For example, although “sunk cost” is an important concept in capital investment, it can wreak havoc on product costing. If a certain machine is fully depreciated and now has a greatly reduced overhead rate assigned by the accounting department, this will likely confuse the purchasing or engineering folks using a Product Cost Management software. It will either cause them to distrust the costing software or your manual analysis or it will drive them to cost all the parts they can using that
This is yet another curse of the difference between the data relevance needs in order to perform good cost or pricing analysis versus the data reliability needs, over which accountants typically obsess. From an accounting point of view the depreciated resource is “free” (or highly discounted). However, from a costing viewpoint, the abilities of that machine will have to be replaced sooner or later. Worse, the distortion in the overhead rate will lead to underestimations of cost, and often, unpleasant surprises late in product development and sourcing.
What to do about non-linearity, discontinuity, and non-monotonic pricing/costing functions:
- Remove them – the first solution is to correct the false arbitrage by fixing the pricing or costing data. For example, in the case of the machine that is fully depreciated, change the overhead rate back to reflect the cost at which a new machine with the same capability would depreciate.
- Highlight them – if the pricing or costing curve has an unexpected kink in it for a legitimate reason, then you should make everyone aware of this and use it to your advantage. For example, in the catalogue motor example, advertise the sale and let people know this is not natural or permanent!
A lot of mistakes in pricing or costing are difficult to notice without close inspection, but remember anything that violates the brains desire for smooth regularity will stick out like a sore thumb… or a good deal.