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Quick Turn Around for an EMS Provider - Brainstorming

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Quick Turn Around for an EMS Provider - Brainstorming | 12 January, 2009

With the High Volume Manufacturing in United States became lesser and the current crisis that the country is dwelling in, Low to Medium Volume - High Mix Manufacturing is very common and small EMS Providers are scrambling to get a Pie of the Job.

I would like to start a brainstorming thread entitled "Quick Turn Around for an EMS Provider - Brainstorming" to help gather info on how to deal with the current situation so that "We" in the small EMS business could arrive and come up with a competitive solution.

So My questions are (Scenarios):

a) A customer called you and the next day provided you with a BOM and the Assembly Kit (for SMT and THA)and Gerber data to be built in just 2 Days and up to 3 Days maximum.

How will you cope up with the limited time that were given you to be able to say that you really did it with a "Quick Turn Around" and Zero Defect.

These are the below processes in my mind that are currently done:

Incoming Inspection and Labelling Gerber Data extraction of CAD Stencil Design and Ordering (1 Day) Generation of Assembly Documents (Visual for SMT and THA) Machine Programming and Thermal Profile Preparation Stores Kit Preparation SMT Set-up and THA Set-up Production Run / First Piece Inspection / Depanelization Final Inspection and Data Recording Packaging and Shipping

All the above (I might have missed some steps) done in just 2 Days and maximum of 3 days. If you can't do it in 3 days tendency is you might lose the job coz there are competitors out there that can do it.

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Quick Turn Around for an EMS Provider - Brainstorming | 12 January, 2009

I've done it many times in the past and I would never recommend to do something like that. always you will have troubles with quality, unless the board is really easy. 3 good persons can do it in 2 days. One create programs and trouble shoot all the machines. Second prepare all test procedures, and thirt helping the other two and dealing with stencil order and shipping preparation. The team should be really good. Again - fast job reflects quality. So the one who is gonna do it in two days, will have the same problem.

Regards, Emil

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Quick Turn Around for an EMS Provider - Brainstorming | 15 January, 2009

What is the shift structure of your shop? If your facility has only one 8 or 9 hour shift per day, then a 3-day turnaround is nearly impossible. However, if you are running multiple shifts that keep the shop alive 24 hours per day, then it is absolutely possible. But, of course, this is also very dependant on the complexity of the product you are going to build.

In my experience, the top show-stoppers were not typically CM issues but customer-created issues: 1. Part shortages: the build would be scheduled on the expectation of a clean kit as promised by the customer. Surprise, numerous part shortages with 1-2 week lead-times. 2. Parts supplied loose or in non-standard carriers and must be placed by hand instead of by machine. 3. Poor or unproven product design: does it require special fixturing or extra handling because of inadequate or non-existent panelization? Do the parts supplied actually fit the land designs? "Yeah, the gerber files we sent you indicated the product was panelized, but the boards we sent you were not. Can't you work around that?" 4. Difficult or confusing documentation from the customer. "What do you need a BOM rev for.? It's the same build you did for us 'N' months ago."

The strongest disclaimer that should always be told to every customer should be "The clock starts ticking when ALL the nuts and bolts are in-house".

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Quick Turn Around for an EMS Provider - Brainstorming | 15 January, 2009

I agree with Wolfman. On everything except that it's nearly impossible to turn kits in three days in a shop that works a single shift. We routinely turn kits in three days. As Wolfman pointed out, the biggest deciding factor on a successful turn around is the condition of the kit upon arrival from the customer. Clear documentation is a must! Packing slips, (not simply a Bill of Material), are very helpful! When I see a packing slip, it shows me that the customer took the time to verify that the parts have actually been verified upon being placed in the kit. It shows me that they know what they've placed in the kit. Throwing all of the parts in a box, and then printing the Bill of Material and throwing it in at the last second does not give me a warm and fuzzy. More often then not, in those instances, we'll discover part shortages that will delay the build. Another important aspect to remember is that EVERYONE involved with the process needs to be "on board" and commit to the three day turn around. I can't tell you how many times I've asked my people to bend over backwards and jump thru flaming hoops to complete a job only to turn it in to finished goods and find out the next day that it didn't ship on time because "Jimmy" was busy pulling another kit and didn't want to take the time to package it. Trust me, the assemblers take note of this and it's that much harder to ask them to do it again the next time. One last comment... Wolfman's statement that the "clock doesn't start" until the last part needed is in house is right on the money! And if they cause delays that cause the start date to slip, they must be made aware that "all bets are off" at that point. Quick turn proto houses can not afford to let a job sit on the line waiting for a single part. If the kit doesn't show as promised, they lose their place in line. It will get rescheduled to the next available opening. Make them aware of this at the very start, and remind them often during the process.

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Quick Turn Around for an EMS Provider - Brainstorming | 15 January, 2009

We do this quite regularly. In fact, it's a core part of our business.

And we do it with a single shift.

How do we do it? With a strong assembly staff, comprised of people who have a lot of experience working in the engineering prototype space. Along with flexible processes. And, finally, a lot of communication with our customers.

To make this happen, we typically take the following steps: 1. Get gerber data with the quote package. This is essential to getting the stencil in hand soon enough to process the kit. 2. Get the kit in hand as soon as humanly possible. Kit verification is completed as soon as the kit is received, to capture any potential shortages. 3. Have kit shortages shipped directly to me, rather than to the customer. If parts are being ordered overnight tonight, they need to be in my hands first thing tomorrow morning. 4. Eschew building the job on the machine. I simply can not turn a program and a load in time to meet this need. I also only have one machine, so, capacity can become an issue. Quick turns of this nature are built by hand. Paste is screened onto the board per normal, and the parts are hand placed on the pasted boards. The boards can be reflowed, per normal, as well; minimizing the hand soldering time. 5. Hand solder through-hole. This is job dependent, of course. 6. Use over-time. Customers that need their boards in 3 days realize that they will be paying a premium for that service, covering my over-time costs. For complex boards, I also have shift best manual assembler is in at 5 in the morning; my supervisor is in till 5 at night. That's 12 hours of available manpower for me, not counting overtime. 7. Any issues are immediately reported to the customers. In most cases, the customers/engineers will have work arounds. Again, if they need boards in this much of a hurry, they are generaly prepared to find work arounds for missing parts, connectors, etc. Communication with the customer is probably the second most important part of achieving this level of turn (comitted personnel being the most important). 8. Divide resources. Dedicate the person who is placing the smt parts to placing the parts, provide a separate resource to take care of touch-up and through hole.

9. Finally, impress the customer with your flexibility and agility in turning their job; so that they come back to you with beta/production runs, or at least come back to you with more prototypes.

All of this, of course, does depend on the complexity of the board. I can do 10-20 pieces of a board with 100 or so placements. Give me a board with 800 placements, and I might only be able to do 1 or 2 pieces in this timeframe.

cheers ..rob

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Quick Turn Around for an EMS Provider - Brainstorming | 15 January, 2009

I think it might be useful to differentiate between proto-typing and volume production builds. With a proto-type, I spend very little time preparing documentation as I'm right on the production line baby-sitting the product from start to finish. This allows me the authority and flexibility to make decisions on the fly and keep the wheels turning.

With a volume build, I have to rely on the team around me to make intelligent decisions. Nothing makes a project lose momentum faster than, as an example, the entire SMT staff going for an extended break because they ran out of a part(translation: the new reel was a different color than the empty reel and that's why they couldn't find it. You can't make this stuff up!) and didn't immediately inform their manager.

Another factor to consider is if you are building turn-key or consignment, and I fully realize not all CMs have this capability.

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Quick Turn Around for an EMS Provider - Brainstorming | 15 January, 2009

I'd agree. I wouldn't be able to turn significant volume in that short a time span....but, then again, I don't see a lot of people that need significant volumes in that sort of time span.

And, agreed on turn-key. I've done a couple of tk jobs in three days, but I try to minimize that. Invariable, when a job like that comes along....I end up bringing in all the material overnight, except for one or two long lead parts. Then the customer adjusts their schedule for the long lead, and I'm stuck sitting on inventory for longer than should have been necessary.

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Quick Turn Around for an EMS Provider - Brainstorming | 19 January, 2009

Proper Prior Preparation Prevents Piss Poor Performance.

I am on the customer side, but have a pretty good idea on what has to happen on the assembly side.


PCB fab takes at least one day, ask him for the Gerber data at the same time he releases it to the PCB fab. This will give you enough time to get the stencil.

Do NOT extract component locations from Gerber. If a customer cannot provide proper component location data from his PCB layout system, he doesn't deserve fast service.

Ask for the partial kit at the same time the PCB fab is ordered. Shortages can follow, direct ship to you is a good idea.

Ask your customers to label components if possible. I always printed labels with my part number and component descriptions, making the EMS kitting job easier.

Use in-house components if possible, at least for resistors and capacitors. This will save you the hassle of dealing with tape snippets from Digi-Key. Otherwise tell your customer about the importance of having leader tape / spare components, and ask them to order in price break multiples (more likely to get uncut tape). Since "birdseed" is so cheap compared to small quantity assembly, I recommend offering it at no extra charge.

Thermal profile ? Unless the board is complex or hard to solder, just use a standard profile. Customers don't expect 99.999% yield on prototypes.

Offer predictable pricing. Set up some reasonable formula, once you get a stable relationship with your customer he won't bother to quote around all the time.

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Quick Turn Around for an EMS Provider - Brainstorming | 19 January, 2009

Thank you for the customer's perspective, Alien. We actually send a short "wish-list" to our customers and includes such necessities as:

1. BOM. Must be Rev-controlled and contain, at minimum, a useable part numbering scheme, adequate description field, and eng. code field. It should also contain a P/N and Rev for the PCB. 2. CAD file in ascii format. We can use an X-Y text file as a last resort, but our software can import up to 50 different CAD formats and will create machine placement files from it. CAD formats are much preferred because they will denote the polarities.

I submit that its the customer's responsibility to properly label their components. We (in process) have spent countless hours assisting our Receiving team trying to match kits to packing list/BOMs when the description is inadequate or missing. If we simply say 'parts placed as labeled by customer' and a labeling mistake existed, guess who's to blame?

And lets throw RoHS into the equation. If the customer says their product is lead-free, then we assume they've verified that all the parts supplied in the kit are compliant. There's simply not enough hours in the day for us to check every part number of a 150+ line BOM.

I agree with using a standard profile. Again, we don't have the time to verify if every P/N can withstand a lead-free profile.

I wish we had more customers like Alien.

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Quick Turn Around for an EMS Provider - Brainstorming | 20 January, 2009

Thank you very much guys. I really appreciate all your inputs. We just have another customer asking us a possible 3-day turn around of their prodcut from PCB Fabrication, Parts Ordering and Manufacture of their boards...just thinking on how can we do that? Our PCB supplier can deliver the boards in 2 working days. Parts are big question mark. oh my...well well...


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Quick Turn Around for an EMS Provider - Brainstorming | 20 January, 2009

Start off by suggesting that they buy the parts as they're going through their layout. Their engineers can output a BOM based on the design, and they ought to be able to buy to that.

That also keeps you off the hook for material liability in case a component (or three) changes during the actual design. I'm sure we've all experienced that!

cheers ..rob

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Quick Turn Around for an EMS Provider - Brainstorming | 20 January, 2009

Here's another question that I should have brought up earlier: are you dealing mainly with brand new products from brand new customers, or new products from established customers?

Here's the reason why I'm asking: once I've got a good part library established for a particular customer, its fundamentally easier to develop new products. We actually give a price break to our more desirable repeat customers for this very reason, plus it creates the incentive for a customer to continue using our services.

It takes only minutes for our documentation/programming software to accomodate a new revision BOM (and I'm fairly certain that most software can do this).

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Quick Turn Around for an EMS Provider - Brainstorming | 21 January, 2009

I totally agree with Wolfman. I recently had the SMA responsibility for a new product from a new customer. The PCB had 600+ mounting positions. It took me almost two days insering them into the part library because an unusual number of the positions had an unique component.

I am not saying it is impossible to manufacture a PBA in 2(3) day but it depends on the product.

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