Z Score lets you compare “apples and
oranges”
The Z Score is the magic bullet of Six Sigma, allowing you to
objectively compare “apples and oranges” and be confident of the results.
In simplest terms, the Z Score demonstrates the “efficiency” of any
investment, showing how well scarce resources (such as Marketing dollars) are used.
Let’s take an example: Think of the fuel efficiency of cars. One car
gets 30 miles per gallon, the other 15 miles per gallon.
This doesn’t mean the car with 30 miles per gallon is a better car than
the 15 miles per gallon car at all. It simply means in the ONE task -
efficiency of fuel consumption - the 30 mpg car rates higher.
That vehicle may
also accommodate only two people – making it entirely impractical for moving a
large group.
In our determination of efficiencies of Marketing investments, we are
trying to accomplish the same thing. Which opportunity will go the furthest on
the same amount of resources?
There may well be compelling reasons that can overshadow this metric –
as in the car analogy. Independent of these other reasons though, we
essentially are trying to determine which investment is the most efficient in
delivering on the set of goals we have identified.
Our application of this theory using the Z Score is “dimensionless.”
What does this mean? It is not restricted to one metric, such as fuel
efficiency. The dimensionless model allows us to compare activities that are trying
to achieve widely different objectives.
For example, in a social media campaign we may wish to capture names of qualified
leads. After analysis, we find that activity has an efficiency Z Score of 2.5.
A separate experiential marketing initiative may have as its goal
employee recruitment and retention. It turns out to have a Z Score of 3.1.
So which is better? It’s the same as fuel efficiency – the larger the
number, the more efficient the process is at achieving the goal for which it
has been designed.
The ability to determine investment efficiency provides Marketing
decision-makers an unsurpassed tool in planning, evaluating and directing the
use of scarce resources.