# Help with negative calculations

#### feulner

I have a situation where I need to update the dividend of a division formula to a lower number. Because the divisor is a negative number, I'm getting the opposite effect of what we expect to see.

The updated target SHOULD provide an improved result but the opposite occurs. I'm trying to find an appropriate calculation that shows the correct result.

Original Results:
-15.12 actuals
14.49 target
-15.12% actual / 14.49% target = -104.35% attainment

Updated results:
-15.12% actual
2.13% target (updated)
-15.12% actual / 2.13% target = -709.86% attainment

It cannot be accurate for someone to have a "worse" % attainment with an â€œeasierâ€ target.

#### skipjack

Forum Staff
Why is actual/target called attainment?

#### feulner

It's a result vs. target which we call attainment. But it's essentially the attainment is the quotient

#### DarnItJimImAnEngineer

You're going to have a discontinuity and a sign flip as your "target" crosses zero.

It's hard to come up with a plan without knowing the nature of the update formula that brings you from 14.49 to 2.13. Any information you can give about the formula or the ultimate goal will be helpful.

#### feulner

Honestly, it's a leadership decision in the business to lower the target from 14.49% to 2.13%. There is no formula that got me to that number.

What I'm trying to do is ensure we are processing the target change accurately and unfortunately, I'm seeing the opposite effect of what we expect to see.

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#### DarnItJimImAnEngineer

I'm wondering if the ratio is actually what you want to look at.

I've seen a definition for "production attainment," which is quantity produced over target quantity. This will be positive because you're not going to produce a negative amount.

Because of the negative sign and the percents, I'm wondering if you're looking at something like this: "We want sales to increase by 2.13 % each year. Last year, it decreased by 15.12 %."
Let's say your baseline was 100 000 units. So, in this scenario, you wanted to sell 102 130, but you sold 84 880. This gives you a "sales ratio" of
$\displaystyle \frac{100 \% - 15.12 \%}{100 \% + 2.13 \%} = \frac{84880}{102130} = 83.11 \%$ relative to your target.

I have no real business management education, and I don't know if that is a standard performance indicator, but it is at least something that makes sense to me. Does it seem applicable to your situation?

1 person

#### feulner

I think it might! THANK YOU!

#### skipjack

Forum Staff
It's a result vs. target which we call attainment. But it's essentially the attainment is the quotient
Suppose you enter an archery competition each year. Your score could be anything from 0 to 100, so you might decide to call your score your attainment. Last year, you scored 40. This year, you again score 40. You've done no better, but no worse. Surely, however, it would make no sense to redefine attainment as current score/last year's score Ã— 100%, because that would be 100% attainment for sitting around for a year wondering why you missed so often. Next year, your score is 80. Wow, that's 200% attainment (using the new definition). However, your attainment the year after that will be 125% at most, even if you never miss. It's time to rethink how you define "attainment". You come up with a clever new formula for attainment. Another year passes and your new trainer arbitrarily decides on yet another rethink... for how many years must this continue before "attainment" gets ditched altogether?