sorting algorithm and factor weight

[keuninkske]

hello

i am a hobby programmer
i am using my skills for the parts department where i am working for
but now i am running into mathematical problems...

i made a program who connects to the databases of my company
i would like to have an list of parts where the top part is the most important to have on stock
and the lowest is the less interesting part to have on stock

there are several factors that i want to take in count, for exampe:
-part price
-part turnover per month
-part turnover per year
-part usage count (more interesting to have 2 parts on stock that you need 100x 1piece of , than having a part where you cannot start the job with only 2 pieces)
-stock blocker if cross reference is known
-machine age where the part fits to
-delivery time ...

at the end i want to limit my stock by the total amount of money that is placed in my stock


at the moment i started to write my algorithm, but it gets mathematicaly difficult, and this is where i need your guys ideas
-pricefactor : i sorted my articles by price, gave them a position number and divided that by 10000, it gives me numbers between 0.0001 and 1.1304
-turnoverfactor: i sorted my articles by turnover/year and gave them a position number between 0 and 236 (1 time used is for example factor 12)
-stock blocker: if a cross reference is known the stock blocker is 0, non known = 1

calculation of the overall stockfactor goes at the moment like: pricefactor x turnoverfactor x stockblocker

now i was working on the parts usage count, i counted the number costumers who bought this item, even if they took multiple, but how to fill this number now correctly in my existing formula


i am certainly not an mathematic guy, all remarks and help is welcome
thanks for your help in advance