Issue link: https://iconnect007.uberflip.com/i/1010078
42 SMT007 MAGAZINE I AUGUST 2018 could be used. It consisted of extremely well- optimized machine programs and carefully balanced lines, where work was split as equally as possible over all machines to get to a single consistent takt time with no losses in between. The 1,000 products would be made, and then disappear into the warehouse. Job done, for SMT. From the business perspective however, unnecessary costs then start to accumulate. It is extremely unlikely that the optimal capacity of the line was exactly meeting the delivery need of the customer. If the customer would take only 900 per day, then 100 additional pieces would have to remain in stock in the factory warehouse. Without careful finished-goods management, the warehouse could soon fill to capacity. The 1,000 per day line capacity was necessary however, as the customer could take the full 1,000 per day or even slightly more. Whenever the assigned warehouse locations became overloaded, the SMT line would be told to stop. Though triggered by a physical threshold, the cost of storage of this "dead" inventory was the significant factor. Often, the SMT line had to stop for just a couple of hours here or there, when the time could be taken advantage of, performing routine maintenance for example, but often, the line would stop for a shift or even longer, getting progressively worse as the fluctuation in customer demand increased. Customers were simultaneously reducing the stock in their whole supply-chain, as the stock held in their buffers became too expensive to maintain, especially considering the erosion in the value of the products. Pushing back on the factory to utilize storage which smoothed out the supply-chain has been a long-term increasing trend. This resultant lost production opportunity was rarely reported in performance reports however. When the SMT line was scheduled to run, it ran with extremely high performance, with completions being reported favorably against scheduled targets. When there was no schedule, there was no target, and therefore from the reporting aspect, no loss. This lead to the great phenomenon whereby visitors to a manufacturing site, would see glowing reports of productivity, but then see an ocean of red lights on inactive machines when scanning around the shop-floor, indicating that most machines were idle. Even with today's more complex, high-mix production environments, the situation is the same. Products are usually now grouped in advance by engineering in a way that makes sense from the perspective of product commonality and is then assigned again to a line configuration that can satisfy the peak demand of the product group. This is especially true in the EMS world, where production for each customer is often ring-fenced from other customers. The essence of the line- rate matching customers demand issue is the same. Performance is again only measured against the schedule. This time, it is worse, as there is no measurement for the efficiency or of the now more complex schedule itself.