How to choose an electric vehicle using a decision matrix

Let's say you want to buy a car and say you know for sure you want a full-on electrical vehicle because gas prices are killing you. You start looking around and some are cheaper, some more efficient, and some more reliable, and ultimately you go with what feels right based on your priorities. That's a typical way to make a decision like that, but there's a more rigorous method you can use for decisions like this to make sure you are getting the car you actually want. This type of process is perhaps more commonly used in organizations where maybe you want to offer your boss a better supported recommendation than just that it feels right to you. For this, we turn to a decision matrix.

Now lets' say we looked up four fully electric cars, a Kia Niro, a Volkswagon ID4 which Elon Musk likes to criticize, and of course a Tesla. Now you do some research and drill down to 5 things you really want in your electric car. Good price, good efficiency, good range, good driving and good reliability.

So let's draw out a table and list these out:

We have the Kia Niro
The volkswagen Id4
And the Tesla Model 3

First thing we'll look at is the low-end basic price on each one of these..
So if this was our only factor, we'd simply go with the Kia Niro.
We could show this by giving it a 'normalized score'.

If smaller is better:
Normalized score = (best price)/(actual price)
Kia score = 39500/39500 = 1
VW ID4 = 39500/41230=0.95
TM3 = 39500/46990 = 0.83

Or more generically:
Normalized score = (best value)/(actual value)

If bigger is better:
Normalized score = (actual MPGE)/(best MPGE)
Kia score = 112/130 = 0.86
VW ID4 = 93/130 = 0.72
TM3 = 130/130 = 1

Or more generically
Normalized score = (actual value)/(best value)

Say there are a couple other factors you'd like to consider as well.
There was range.... where the Tesla Model 3 comes in better at 310 compared to 240
There's reliability... which the Kia Niro is actually the best at with a full 5/5 according to consumer reports, which is where I'm getting all this info
And there's basic owner satisfaction, which the Niro's a tad lower in.
(I was going to put their road test scores on here also, but they are all basically the same so it's not a big factor)

Now we can get normalized scores for each of these other three components, but which of these normalized scoring methods would we use?
Bigger is better for these, so we'd use the same formula we used for the overall MPGE
And crunching those numbers, here are the scores.

Now we could simply add all these normalized scores up and see who wins, right? We do that and we get..
4.44
3.85, and
4.44

So we have a tie between the Kia and the Tesla. So either seems like a decent option, but notice we allotted an equal 1 point to each of these 5 characteristics. It's likely these aren't all equally important to you though, right? So in order to differentiate between these, we have to consider which of these are more or less important.

So perhaps you're thinking these are all important, but that initial price is importanter, and the 'owner satisfaction' is maybe a little less important since it's rather subjective. So we can now assign weights to each of these factors. There are five factors so if lets say the best possible score would be 1, then the default weight for each factor is 1/5 =0.2. So lets assign that default weight to the MPGE, Range, and reliability. All important. But price is more important than satisfcation, so we boost that to 0.3 for price and lower owner satisfaction down to 1.

Now we can determine our new weighted score by multiplying each of the normalized score by the associated weight of it's factor. So for the price weighted score, we multipy
Price weighted score = (price weight)(normalized score)
Kia Niro price weighted score = (0.3) (1) -0.3
VW ID4 price weighted score = 0.3(0.96)=0.29
Tesla Model 3 price weighted score = 0.30(0.84)=0.25

We can do the same for the other weighted scores, so for example,
Kia Niro MPGE weighted score = (MPGE weight) (normalized score) = 0.2(0.86)=0.17

We can then fill in all these weigthed scores accordingly

And then we can add up all these weighted scores, and we find that the Kia Niro wins out.

So maybe you initially really wanted a Tesla, but you crunched the numbers here and find that, based on what's really the most important to you, the Kia's the car for you. That's why a decision matrix like this can be helpful, because it can help make sure you choose the right product based on both the data and your actual, objective priorities. But then again, maybe you just want the Tesla anyone because it's cool or you’re an Elon Musk fan, and you want to show it off to all your friends, so if you do buy it, now you at least now why.

Hope this was helpful, and until next time, take care,