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April 2000

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Subject:
From:
Ahne Oosterhof <[log in to unmask]>
Reply To:
Date:
Wed, 5 Apr 2000 08:24:52 -0700
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I must be missing something.

I am sure you get your passive parts and the semiconductors on reels and
your connectors, etc. in boxes. What is so very different about getting your
boards in panels?

By the way, if you insist on counting boards by the panel, how do you deal
with those slightly less perfect panels that have a big black cross on one
of the boards because it is a reject and the vendor was nice enough to let
you know? Does that become a 0.75 panel (or some number like that)? And if
the vendor is really nice and sends an extra panel because there are a few
rejected boards in the batch does your receiving department return that one
because the quantity does not match the order?

Ouch, too many "what ifs".

Ahne

PS: many MRP system have the ability to handle parts in multiples, so
pencils get ordered by the dozen, cable by the reel and boards by the
"fours" (or whatever).


-----Original Message-----
From:   TechNet [mailto:[log in to unmask]] On Behalf Of Steve Kingdon
Sent:   Tuesday, April 04, 2000 7:19 PM
To:     [log in to unmask]
Subject:        Re: [TN] Panelization of Board v/s MRP system

Finally, after 2 years of lurking, a question I can respond to!

Ken,

Talking as a PCB designer, this is how we do it here.

We do a lot of panelised boards, we design the routing/milling/rails/tooling
holes etc. and lay-up/panelise the copper layers etc, so there is no
guess-work to be done at the board vendor's end. This also means we can view
(using Gerbtool) and verify exactly what we should receive with minimal
interaction with our board vendors. (This is not to say we do not talk to
our board vendors!)

We also use Oracle as our database/MRP system. I have a minimal
understanding of how a MRP works, but I know this much about how our system
operates.

Take a panel of 4 PCBs. The panel has a part number that we order by, say
123-45678-90. (We also give the individual PCB a part number, typically only
one off the panel number eg 123-45678-89, but the MRP side of the system
doesn't know about this. They are used for tracking individual boards/board
vendor batches out in the field.)

Say also that product M987-10 uses 1 pcb out of panel 123-45678-90, and we
want to build 75 off M987-10.

We also have bills of materials (BOMs)in Oracle that the MRP trawls through
and decides what to buy when and how many etc.

Now to the point........In the Oracle BOM for product M987-10 we call for
0.250 of panel 123-45678-90, thus we get one board per product. Also we want
to build 75 in the next job so the MRP works out that we need to buy 75/4 =
18.750 panels, which the system rounds up to 19.

I think that the system is also supposed to be smart enough to figure out
that if we order 25 we get a price break, but whether we can order this
quantity is dependant on the effectivity date of outstanding ECOs blah blah
blah, plus a whole bunch of other factors.......... I don't know whether
this bit is functioning correctly or not.

So.... all the board vendor sees is an order for 19 panels of 123-45678-90,
so hopefully he doesn't even have to think too hard about it all.

At our (engineering planning) end we need to set up the Oracle BOM with the
right quantity of the panel eg 0.250, which we do when the panel is entered
into the BOM.

On the assembly side, our smd boards go straight to the line (gulp,
nervousness for PCB designers!) so there are no kitting issues for these.
For leaded panelled boards, stores will get told the number of panels, in
our case 18.75, so they would kit 19 panels. The 19 boards are delivered to
the line as one bundle.

Admittedly you do get funny numbers like 1/12 = 0.083 or 1/15 = 0.066, but
no one really needs to deal with these numbers, in stores, just round up; in
assembly keep populating boards until the parts run out; and in engineering
planning the use of a small calculator is recommended to work out non
obvious fractions!

There is debate whether it is better to waste a few boards from a panel,
save the unpopulated boards in the panel, or even to populate a whole panel,
and then try to manage/store the left overs. I am told that we generally
throw away any unused portion of panel, the overhead of managing unused
portions of panel outweighs any reject material savings.

Hope this helps

Steve.

> Steve Kingdon
> PCB Designer
> ----------------------------------------------------------------------
> ----------------
> Invensys Energy Systems (NZ) Limited, 39 Princess St, PO Box 11-188
> Christchurch 8030, New Zealand
> Phone: (++64) 3 343-3314, Fax: (++64) 3 343 5100
> DDI:   (++64) 3 <343 7440 ext 8401>
> Email: [log in to unmask]
> Website: http://www.invensys-energy.co.nz
>


-----Original Message-----
From: Ken Patel [mailto:[log in to unmask]]
Sent: Wednesday, 5 April 2000 09:42
To: [log in to unmask]
Subject: [TN] Panelization of Board v/s MRP system


Guys,
We had a meeting yesterday with design layout house. We wanted a small board
to be panelized while he resisted saying it will also create a trouble for
the MRP system (besides his own!).

My question to you guys, how you or your buyer handle buying when the board
comes in a panel? I believe he/she put an order for the quantity needed and
fab house make sure that they meet the total board count. Also, how about
the kiting for the assembly. Applicable MRP system is Oracle.

There are small size boards which can not be run on machine except on panel
so there must be a way to handle it.

re,
ken patel
______________________________________________________
Ken Patel                       Phone:  (408) 490-6804
1708 McCarthy Blvd.             Fax:    (408) 490-6859
Milpitas, CA 95035              Beeper: (888) 769-1808

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