Formula for taking inventory

I work for a waste water company and we would like to begin using Excel to keep track of inventory as well as monitor any work orders. To do this I have created a spreadsheet with 6 tabs. I would like to be able to type what equipment was used during a work order (For example; one bolt), and have that one bolt deducted automatically from the inventory list on a separate tab. I have included attachments of my example in the spreadsheet I created for the reader to understand completely. You can see on the sheet labeled "inventory", I have the bolt in question with a total quantity of 25. In the spreadsheet labeled "WORK ORDERS", you will see that I have the example in question have a quantity used of 2. I need the formula for the deductions to be made automatically, not just for the cells I have mentioned, but for all future cells in those columns. Obviously this is only going to work if Excel is able to recognize names of parts as well. For instance, if I type "2 bolts" in the equipment used section, it must be able to recognize the "bolts" part, in order to deduct it from the proper column on my inventory list. If this is not possible, I would greatly appreciate any advice on how to correct my spreadsheet. Thank you so much in advance!!!!

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How many unique items will you store in inventory ? Just curious.