In today's economic situation, the subject of 'operating costs' for investments in a pick-and-place line has gained a great deal of importance. Owing to the ever-increasing cost pressure on the manufacturers of electronics goods, not only are the actual investments for machinery themselves decisive, but more and more, so too are the additional direct and indirect operating costs.
As before, it is observed that most companies ultimately only consider the investment costs and the assembling capacity at 100% machine availability as the means by which they compare machines offered by various suppliers.
But the approach can cost a company a great deal of money. A listing of all the costs in a 'lowest cost of ownership' model has shown that these costs can vary, for equivalent machines in the market, by up to 100 000 euros per year. If we extrapolate these costs across the normal life of the pick-and-place machine of about seven years, the costs add up to 700 000 euros.
The costs can be divided as follows:
Production costs (direct)
* Price/performance ratio.
* Efficient and fastest product changeover/new production start-up.
* Flexible and large application range.
+ Overhead costs (indirect)
* Simple training and programming.
* Minimum maintenance requirements.
* Minimum spare parts and service costs.
* No line downtime owing to a machine failure.
* Compatibility of old and future systems.
* Modular concept.
= Total cost of ownership
Only once all these factors have been taken into consideration is it possible to decide which supplier offers the best 'return on investment'. Every supplier will claim to offer a system that 'hardly ever fails' and has the 'minimum costs'. Unfortunately, these claims can usually only be evaluated after the user has actually bought the systems. A few factors that need to be considered in detail are listed below:
Efficient and fastest product changeover/new start:
For production of batch sizes < 5000 and new production start-ups which are introduced on the mass production line, fast and safe product changeover is of decisive importance in order to minimise the line standstill time. The smaller the batch size, the less important the actual assembly time (or cycle rate) becomes. A good value for a complete change-over, including 100% equipping inspection, would be a line standstill time of less than 5 minutes. This can only be achieved with support from all corresponding technical modules on the pick-and-place machines, eg, replaceable feeder banks, intelligent machine and feeder concepts as well as highly developed line software. In the case of new product introductions, it should be possible to directly measure dimensions of new components on the pick-and-place machine and input changes directly at the machine module in the production mode. This ability minimises the time to make programming changes which are common for new production runs (such as reversed components, or wrong dimensions). Juki's FlexLine 2000 module offers all of these capabilities.
Minimum maintenance requirements:
Pick-and-place machines are becoming ever-faster and have to cover an increasingly larger range of components. However, this does not mean that the technology of the machines from a user's point of view has to become more complicated. Today, the demand is for low-maintenance, robust and well-built systems. A maintenance effort of 30 minutes per month (machine standstill) must not be exceeded, so that smooth 3-shift operation is guaranteed. In order to verify such data, it is necessary to refer to users of these systems. Maintenance work means unproductive time that results in higher costs. Juki's FlexLine 2000 module is considered one of the best low-maintenance systems in the market.
Minimum spare parts and servicing costs:
During the life of a machine, the spare parts costs can be massive. Values of 4-6% of the investment costs per year are not uncommon. What is even worse is the downtime of the production lines associated with the need for a spare part. A good basis for a comparison is the costs per module, which, on an average, do not exceed 3000 euros per year across the life of the machine. This must include spare parts and wearing parts. It is imperative to check references to verify such data. Juki is the first manufacturer in the market to offer a 3-year guarantee (on its FlexLine 2000 module) out of a belief regarding the minimal spare parts costs and associated machine downtimes.
No line standstill owing to machine downtime:
Systems must be built in such a way that in case of any element failures - eg, pick-and-place heads - production can still be continued, albeit with a lower capacity. Emergency programs must facilitate bridging or by-passing of modules, so that a line standstill can be avoided under any circumstances. Juki offers multiple, independent head systems with laser technology, each of which can be switched off in production mode.
Compatibility between old and future systems:
There is nothing more annoying than the existing supplier not maintaining compatibility when new systems are introduced, but unfortunately, this keeps happening. There are different, incompatible feeders, feeder banks and software. This means that there is lost flexibility between the machines or lines and hence, additional costs. Juki has maintained the compatibility of the FlexLine Module since 1993 (four generations), even though the systems are continuously being developed further.
Summary
The operating costs and the 'cost of ownership' must be examined in detail in a machine evaluation, since they are a decisive factor in successful investment. Neutral information must be obtained from references. Juki addressed the requirement for the 'lowest cost of ownership' in the early development phase of the pick-and-place machines.
Among the top three manufacturers of SMT pick-and-place machines in the world, Juki's new pick-and-place modules of the 2000 series consist of four pick-and-place models that can be combined with one another as needed. Depending on the type or combination of machines, assembly capacities in the range of 6400 to 50 000 components per hour can be achieved. The components that can be processed range from 0201 chips to 150 mm long connectors, 75x75 mm ICs, BGA, CSP, CCGA as well as other special components.
For more information contact Allan McKinnon & Associates, 011 704 3020.
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