In manufacturing, enhancement of production is an endless undertaking. In any case, a commendable one. A single improvement at a production line system can mean tens or a huge number of dollars in income. Furthermore, its during streamlining when you may go over the term Overall Equipment Effectiveness –OEE. Hence take a look, how can it help with evaluating productivity? The OEE calculation varies depending on the manufacturing process. This is because different manufacturing overall equipment techniques have different ideal cycle times, production yields, and so on. As a result, we will cover the manufacturing process, calculate OEE methods, and how OEE is determined for each production process in this blog.

The manufacturing process includes

  • Repetitive manufacturing
  • Discrete manufacturing
  • Job shop manufacturing
  • Continuous process
  • Batch process

It is very important to understand the process in order to apply the right form of the OEE Calculation for the right results.

OEE calculation in each manufacturing process

Repetitive Manufacturing

Repetitive manufacturing is the manufacturing shop floor process work in which products are delivered for rapid production flow. Continuous manufacture of the same product over a lengthy period of time is referred to as repetitive manufacturing. There is no end value for the quantity produced. It is predominantly utilized for production scenarios with high product, high repetition rates, and low product complexity.

OEE Calculation

AvailabilityAvailability is the proportion of operating time and the planed production time that are available for production in the manufacturing process. The difference between the planned production time and the unplanned stop time is the operating time. The percentage of time a machine can actually manufacture parts compared to the total time it should take to produce parts.

Availability = Operating time / planned production time

Operating time = planned production time – unplanned stop time

Performance -The second part of OEE looks at the actual running speed of the plant or equipment against its predetermined working speed. The predetermined run speed is frequently referred to as ideal cycle time. Performance is the actual throughput of the plant during the time it ran, contrasted with the most extreme throughput that it might have accomplished running at the ideal cycle time. Performance losses are divided into two categories: micro stops and slow cycles.

Performance = (Total parts / operating time) / Ideal cycle time

QualityThe third part of OEE estimates quality, which is basically the extent of real production throughput which meets the client detail precisely and is correct the initial time. Quality losses fall into two classes production rejects, and start-up rejects.

Quality = Sum of good parts / Total parts

Discrete Manufacturing

Discrete manufacturing is a production method that is based on individual production orders. To put it another way, it’s the manufacture of different goods. It is the place where completed distinct products are made and gathered. Almost every product sold in stores is an example of discrete manufacturing. Is implied by discrete manufacturing that the item being made is a distinct unit.

OEE Calculation

Availability – The comparison of machine operating time and time in which the machine is actually making products.

Availability = Runtime / Planned production time

PerformanceActual output versus what the machine should be producing in the same amount of time.

Performance = (Ideal cycle time * Total count) / Runtime

QualityThe number of parts per product manufactured against the number of parts per product produced according to the client’s specifications.

Quality = Quantity of good parts / Total quantity made

Job Shop Manufacturing

A job shop is a type of manufacturing process that produces small batches of a wide range of unique products. Furthermore, this is concerned with customisation and limited production runs. The final products come produced in little groups (of varying quantities). Customers customize their orders to meet their particular necessities. This implies a business will deliver a small volume of products that are not normalized.

OEE Calculation

Availability – The planned downtime factor refers to lapses in the schedule and allotted breaks. Some causes of downtime have a negative impact on OEE in the job shop, while others do not. For example, if a machine is down for an extended period of time, the operator may be unable to locate the necessary tools to set up the machine, which reduces OEE. However, if a machine is idle simply because it has no more scheduled work, it is still available if needed. As a result, depending on the situation, this may not have a negative impact on OEE.

Performance -In general, we need a standard “ideal” cycle time to calculate performance. But nothing is standard in the job shop. Instead of trying to apply a single ideal performance rating to each machine/part combination, we should only apply a unique ideal performance rating to each machine/part combination.

Quality – Quality can be defined as the proportion of good parts produced in relation to the total number of parts produced.

Batch Manufacturing

Batch process production is a way of producing things in predetermined groups or quantities over a set period of time. Batch might thus go through a succession of steps in a major manufacturing process to produce the desired final product. However, as a batch progresses, there will be a break between each stage. Batch production is utilised for some kinds of manufacturing that might require more modest measures of production at a time to ensure explicit quality norms or changes simultaneously.

OEE Calculation

Availability – It is the operating time divided by planned production time. In addition, the operating time is the difference between planned production time and downtime. Further, the downtime occurred may be stop time or setup time. And also the planned production time refers to the time between a batch being scheduled and time it goes to a running state. Generally it refers to the production time without any downtime. Hence the availability can be calculated as follows

Availability = operating time / planned production time

Operating time = Planned production time – Downtime

Planned production time = Batch duration – Scheduled time

Performance –In addition, the rate is essentially an ideal throughput for each process unit in terms of capacity over time.

Performance = Total product quantity / (theoretical production rate * operating time)

Quality -We can determine quality by dividing the actual product yield from target product yield.

Quality = Actual product yield / Target product yield

Continuous process

A continuous process is a flow production method that allows materials to be manufactured, produced, or processed continuously. It’s the same with the creation of undifferentiated goods. Cycle time should be measured in terms of flow (volume/time).

OEE calculation

Availability – we can calculate it by dividing actual running time from time available for running.

Availability = Actual running time / Time available for running

Performance – Generally we should calculate performance by relating actual performance of equipment. But we cannot apply this metric to continuous process due to the varying performance of multiple equipments forming process chains. Hence we can calculate performance as

Actual Hourly rate / Average of Hourly rate overtime

Quality – We can calculate Quality by dividing good parts from total parts.

Quality = good parts / Total parts

Hope this article provides a detailed view on OEE measurement for each production processes.

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