Eight Big Losses

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When the equipment is intentionally turned off, it is called shutdown loss. It is the time when production is not expected from equipment such as deliberate shutdown, planned maintenance, shift change, lunch-tea break, training. Shutdown loss should not affect equipment effectiveness as it is a planned loss. Equipment efficiency should not decrease due to shutdown loss when calculating OEE. The low efficiency of the equipment with planned shutdowns causes the data to become meaningless and a piece of equipment that we do not want to use voluntarily, "Why is its OEE so low?" It may cause us to question.


As the name suggests, it is the time that the malfunctioning equipment loses during the time it cannot produce. Maintenance should not be confused with malfunction. Failure is an unplanned constraint that results in loss of function and reduces equipment efficiency. Maintenance, on the other hand, is a constraint that is preferably done in a planned or autonomous way and enters the loss of closure.


If the production equipment produces more than one product, it is necessary to change the model. For a model change, it is necessary to change the mold, fixture, jig, equipment etc. on the machine. The time spent during this change is a waste of setup. After the equipment is changed, the setup is not complete. In order for the equipment to produce quality products, it is necessary to adjust the mold-fixture. This is tuning loss. Long-term adjustments made without setup will also lose setup. Setup loss is briefly “the time elapsed between the last quality X product produced and the first quality Y product produced after the model change” The way to reduce the setup loss is through SMED.


Equipment cannot output without input. When the input of the equipment is not received, the efficiency of the equipment is also limited, since the production does not take place. If the machine cannot produce because the material, intermediate product and raw materials are not available, there is a loss of supply and filling. This subject, which can be discussed in more detail in the theory of constraints, constitutes an obstacle to the effective use of machine capacity. If the machine in question is the bottleneck equipment, it is called a Capacity Constraint (CCR). If there is a loss of supply despite the limited capacity of the equipment, this may cause the entire production to be interrupted. Although the machine in question is not a bottleneck, supply loss may occur due to many reasons (not holding enough intermediate stock, not completing the setup foreseen in the previous process, not being in place of the person or equipment to transport the material, etc.).


Some equipment, due to its nature, cannot output despite working until it is ready for production. This loss is frequently encountered in facilities such as ovens, paint shops, etc. Even if there is no need for a setup on the equipment, it can produce scrap products before starting production, or the plant is made ready for production by consciously inputting scrap produ into the equipment. After turning on the combi boiler in your home, just as you wait for your combs to heat up with full efficiency, the equipment also suffers a start-up loss until it is ready for production. The initial loss should be analyzed in detail like any loss. One of the ways to reduce the start loss may be to prepare the equipment before the start of the shift.


If the equipment is operated continuously or periodically slower than its ideal speed, or if it is consciously allowed to produce below its capacity, the equipment loses speed. The reason for the loss of speed may be that the equipment is not well maintained, the operator may be inefficient, the equipment may be worn, it may be operating under its installed or ideal capacity. Loss of speed limits the effectiveness of the equipment during the aforementioned factors.


Some speed losses are immeasurably small and instantaneous, recording and analyzing them may take more time than the loss occurred. This type of loss is called a Çokote loss. Stalls, instantaneous slowdowns, fluctuations in speed, material jams, blockages, sensor blockages, sensor pollution, etc. are examples of instant stops. Some multitudes can be fixed with small operator interventions, or they may need to be analyzed in detail with technical support. Since the Çokote loss is kept collectively, the details are elaborated during Kaizen studies and the problem is divided into parts.


Not all products produced by the equipment may be of good quality. Some products may be scrapped, while others may have to be reprocessed. This loss is called scrap-rework loss, as such products will in any case waste the equipment's time. Since the scrap and the products to be reprocessed during the setup and start-up are recorded under that heading, it does not need to be repeated in this section.

These 8 major losses, which restrict equipment efficiency, not only eliminate the continuity of production, but also point to the problematic points. Analyzed with capacity utilization