--- In [email protected], "Frank Bennett" <[EMAIL PROTECTED]> wrote: > > --- In [email protected], "Rick Collins" <gnuarm.2006@> > wrote: > > > > I have not read this entire thread, but at risk of showing my lack of > > understanding, let me make a few comments. > > Rick, This is a new thread I just started, thanks for the feedback.
I get a lot of email for this group (and other, similar groups) and I often don't have the time to fully digest them all. I guess I just assumed your post was part of a thread. It sounded pretty well thought out like it was part of a lengthly discussion. It shows you have given this some thought. > My intent is to get us developers to think about changes to KiCad > that in my mind are not astronomical... I guess that is my point. Adding functionality to help with the generation of BOMs and procuring parts is something that needs to be done with the full realization of the inherent complexity of the problem, or you will have a "half baked" solution that really doesn't do anything useful and may even create *extra* work (ala the Orcad approach). > > In the above, there is not only a manufacturer's part number field > > which will change depending on available parts, but also a disti's > > part number which can change depending on the packaging you order, > > reel, cut tape, tube, etc. Then even the disti is included which can > > also change (if I am ordering these parts from Mouser, why not give > > them the entire order?) (btw, you are paying too much for your > > resistors ;) > > yeah, I just cut and pasted this from a quick Digikey search. > This data example shows that Digikey in general, has done a > great job in expanding the manufactures part number to a unique > Digikey one...The problem is that every company/distributor has > created their own part number, yes that allows multiple sources > of approved vendors, maybe with inventory and pricing but decoupled > from the EDA schematic capture and PCB layout. There is no universal > part numbering database to describe the part that is needed for > the design under consideration nor is there really a need for one. > The number is only convenient for describing the group of vendors > and each vendors unique but compatible part number. Yes, there is a part number for each manufacturer because they each design to their own spec. There is a unique part number from each disti because there is no standard and they all carry different sets of components. Then on top of that, most companies assign their own part number to a given part or socket on the boards they build. The company's part number cooresponds to the set of all parts that can be used in this socket and does not have to be a single manufacturer's part number (or disti's). > > The design I just got into prototyping had several last minute part > > number changes because of supply issues changing between the engineer > > (me) selecting the parts for the final BOM and the buyer (me) placing > > the order (about 1 week). It would be counter productive for > > management (me) to require the engineer (me) to change the schematic > > just to make things easier for the buyer (me). > > Since the schematic/PCB tool is usually decoupled from the parts > database my minimal goal would be to minimize the communication > between the engineer and procurement. Each engineer needs to look > up the manufacture spec then make/find a schematic symbol and PCB > footprint for the design then the component guy has to figure out > what part the engineer is talking about....lot of room for mistakes: > wrong part and/or wrong footprint and/or wrong power or precision.. But that is the rub. The schematic package needs to be integrated with the parts database to allow the designer to have as much information as possible. In a job I had a couple of years ago they used Orcad coupled to their in house data base. This could, at least in theory, give the designers a selection of parts that are currently stocked and known to the system which would make procurement easier. Don't slight the need for this as it makes *everyone's* life easier... especially when you do all of the jobs in a company. But the Orcad approach left something to be desired. Every part to be ordered ended up in the system and it was hard to tell what was actually used in designs and what was just a sample purchase. It was also rather slow and very inefficient in searching for parts based on parameters. Digikey is the king here. If I remember, they offered a connection between their data base and their customers in some manner. But I have no idea how well that works or if it still available. No company operates by tossing designs over the fence anymore. If the designer gives a design to a components engineer without the part selection being very clear, they will get some serious grief! If they try to put a board into production using parts that the buyer can't get for 12 weeks, they will get some serious grief! Everyone needs to play together even if they aren't the same person like is the case with me. > Web sites like "partminer.com" and new EDA tools can make this bridge > easier. I haven't been to Partminer in a long time. I seem to recall that they charge for the services other than just looking up suppliers of parts. I have never been willing to pay them since I can't really tell what I would be getting. Is there an easy to use, open source data base? I think it would be great to think about integrating schematic, layout and database into a unified package. But the layout and schematic are the first parts to be 100% integrated.
