Re: Part/Product Management
I'll cordially disagree with lyndon on part numbers. Using arbitrary numbers leads to the classic military "ordered a case of toilet paper, got a tank" scenario (oh, those were 'S'es, not '5's!).
Simple labels work as long as you have less than a dozen things to remember, but electronics has lots of options. I use seven different kinds of resistors on a fairly regular basis (5% carbon in 1/8, 1/4, and 1/2 watt, 1% metal in 1/8 and 1/4 watt, 0805 and 0603). I limit my values to the E6 series wherever possible (10, 15, 22, 33, 47, 68), but with seven decades (1 ohm to 10 megohms) that gives me about 300 combinations to choose from. I don't have full sets of course (I'm not likely to use a 1/2 watt 1 meg resistor any time soon), but if you tell me you want a 1k resistor I'll ask "what kind?"
Thing is, all those options already have values. If I tell you my inventory numbers for two parts are R05-TH-METAL-125mW-683 and R01-0805-THICK-1004, you can work out what I'm talking about.
With chips, you have to be sure you're getting the right package.. I just built some boards designed for 74LVC1G14s in an SOT-753 package, but all I had on hand were SOT-353s. I made it work, but didn't enjoy the process.
Short arbitrary labels are good for circuit diagrams (R1, R2, ... R97), and the BOM is the dictionary where you connect those labels to descriptions that will give you enough information to order the parts you need. Personally, I try to roll the facts I'll need into my inventory codes so I don't have to get a second dictionary to connect the descriptions to something I can order.
Since I tend to order most of my stuff online, I keep links to the pages where I can order parts in my inventory along with the ID and the number on hand. It saves me another few steps of shuffling references when I need more toys.
When you void a product warranty, you give up your right to sue the manufacturer if something goes wrong and accept full responsibility for whatever happens next. And then you truly own the product.