# Meaning of W in SFPW, or a synonym that starts with a W

Big disclaimer: when I was proofreading my question it sounds like I am doing a crossword puzzle. So I added some extra information to avoid confusion.

I am making an Excel sheet that assists in Risk Assessment (this particular approach of Risk Assessment is based on the RA by Bosch Rexroth as described in the book 10 Steps to Performance Level). Basically all you have to do is write a few values in certain columns and it automatically calculates the risk. The names of these columns are S, F, P, and W.

As you might have guessed, these names are singular abbreviations. I added a description tag that is visible when the column is active. The descriptions are copied from the book mentioned earlier:

``````S    Severity of injury          <- Makes sense
F    Frequency with duration     <- Makes sense as well
P    Possibility of avoidance    <- Same here
W    Probability of occurrence   <- What?
``````

I can imagine that P was taken for Possibility of avoidance. But I am absolutely flabbergasted why the authors would use W as abbreviation. I can't change W to O (occurrence) because I must/am forced to copy the example sheet as described in the book. I searched around for what W could stand for, but the online acronym and abbreviation lists didn't provide an answer.

Not being able to change the abbreviation, I decided to change the description. Which would be something like:

Wrobability of occurrence

Woccurence probability

I searched around in online dictionaries and thesauri, but I couldn't find anything close.

Besides all this, I can only assume the authors had a valid reason to choose W over something more "logical" as O. It feels like I am missing the obvious.

So in conclusion:

1. Does anyone know what the W in SFPW stands for? (SFWP is also used)

2. Or does anyone know a synonym for probability or occurrence that starts with a W?

• Whether it will occur ? - PS Two r's in occurrence Commented Aug 29, 2013 at 8:24
• @mplungjan, that might work! But the possible values are: `Negligible`, `Rarely`, `Possible`, `Likely` or `Very high`. "Whether it will occur" implies a Yes or No answer. But it's still better than nothing. Commented Aug 29, 2013 at 8:31
• Probability Weight: Negligible, Rarely, Possible, Likely or Very high Commented Aug 29, 2013 at 9:10
• Wager - long shot... Commented Aug 29, 2013 at 9:12
• It may well just be a maths thing: "Let W denote the probability", unless you are sure they are initials, W is one of the classic letters used for variables in math. Also, "Frequency of duration"makes no sense at all, don't you mean just Frequency? Commented Aug 29, 2013 at 11:49

W is commonly used for probability in physics. It comes, as speculated earlier, from the German language because of the high number of German physicists. For example:

http://en.wikipedia.org/wiki/Boltzmann%27s_entropy_formula

"The value of W was originally intended to be proportional to the Wahrscheinlichkeit (the German word for probability) of a macroscopic state for some probability distribution of possible microstates ..."

Since Bosch Rexroth sounds decidedly German, I would think that the W stands for Wahrscheinlichkeit (German for probability), which answers your first question, but doesn't really help with your second, unfortunately.

• Actually Bosch Rexroth is Dutch. But the Dutch word for Probability is Waarschijnlijkheid. But the book is written entirely in English (i.e. not translated from Dutch to English as far as I know), so it seems unlikely imho. EDIT: the book stated that it is translated from German, so perhaps you're right... Commented Aug 29, 2013 at 8:47
• Bosch Rexroth is a German company. But wouldn't Possibility be M if they were talking German? Or did they use the German word because they'd already used P? Commented Aug 29, 2013 at 8:53
• I think the Matt-Jjj theory well probable. Commented Aug 29, 2013 at 9:27
• @Andrew - That did occur to me, too. I think your explanation is most likely, though.
– Matt
Commented Aug 29, 2013 at 9:27
• I guess P was already used, so they had to find another letter for probability. Which is why they went to German (or Dutch). Commented Aug 29, 2013 at 18:51