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SMT electronics assembly manufacturing forum.


SMT LIne Production Rate

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#64097

SMT LIne Production Rate | 6 April, 2011

Hi

Has anyone managed to accurately produce a spreadsheet or formula that will accurately calculate the amount of boards your SMT line will produce an hour. I work in a high mix low volume industry and we are constantly taking on new jobs but have no accurate way of saying how long each new job is going to take. I have started to break down the line into its different operations such as printing solder paste, setting pnp machine and running pnp machine. When calculating a production rate for running the pnp machine however it is proving difficult as different components take different amounts of time. Does any have any ideas? Thanks.

Don

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#64100

SMT LIne Production Rate | 6 April, 2011

A "quick and dirty" method would be to start tracking your assembly time per job. Divide by the number of PCBs built, divide again by the number of components per board. This should give you an average placement time per part. You can then use this number to "forcast" approximate build times. It won't be dead-on, because there are a number of variables involved, but it should give you a pretty good idea how long a job should take to produce.

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#64109

SMT LIne Production Rate | 7 April, 2011

Hi Don, record the time from when board one has exited to when board two gets to the same point (this is your total cycle time including transferring in/out, fiducial checks etc). You can then multiply this out per hour. I would suggest you want to then add an efficiency to the figure (perhaps 75-85%) to include components running out/breaks??? Do this for your top running work to start to see how many hours a day/week you need on current forecast. You'll then get an idea of what new jobs you can take on.

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#64129

SMT LIne Production Rate | 8 April, 2011

Thanks Everyone

I have attempted to take an average for the all the components but this but theres such a range of times I don't think this is accurate enough maybe I should try for the different types of sizes of components. As for the cycle time I will try this but I really need to find a way of reducing cycle time. Thanks for all the input great stuff.

Don

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#64132

SMT LIne Production Rate | 8 April, 2011

We have Mydata and you can print a report telling you the average placement time per part number. I monitored a few months of jobs, broke things into package type, grouped packages with similiar times (such as chip components up to 1206, SO-8,14,16 etc.) and have a very elaborate database where I can enter the number of each package type to get placement time. Getting print time, transport time etc. is easy so it is either single or double sided for that. Setup is a matter of measuring again by similar type (8mm, 12mm, tube, trays etc.) and entering this into you database to get setup time. Add some time to compensate for changing reals, trays etc. during the run and add in lost time for breaks, expected downtime/maintenance events and on-line programming and you'll have your expected throughput. It can be very accurate and realiable once you've established all of your standards and is also how we quote jobs to our customers.

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