OEE ( Overall Equipment Effectiveness)

Performance Ratio is the ratio of the number of products produced by the machine during the shift to the product capacity it can produce in the same period. For example, if the packaging machine has the capacity to produce 400 products in 8 hours, but it produced 350 products in the measured shift, the performance ratio is 0.875. Quality Ratio is the ratio of the number of sound products produced in a shift to the total number of products. If 1000 products were produced from the machine in the shift and 50 products were lost, the quality ratio is 0.95. When we multiply these three measured values, the OEE value will be 0.9655 x 0.875 x 0.95 = 0.8026. The minimum OEE value accepted for a machine in a shift to be efficient is 0.80. An OEE value below 0.40 is alarming and action must be taken. Very rarely, the OEE value can be above 1. A very high performance jumps the result of the parameters above 100%. However, this highlights the need to reconsider the set capacities of the machines. A machine with a capacity of 500 during the shift can reach 800-900, indicating that the set number of 500 is incorrect. In my opinion, the highest performance value that can be measured is 1.10.

In our previous articles on OEE, we gave definitions and examples of OEE and its subcomponents, and we talked about when improvements should be made. While talking about all these, our main idea was always the machines. So, do only machines have OEE values? No... Along with the machine, operators also have availability, performance, quality ratio and therefore OEE value. In fact, the OEE value of the operators is more significant than the machine. Because, while the methods to improve machines are limited, the methods are unlimited in human beings. While it is possible to increase the OEE of a machine by 25-30% at most, it is possible to increase the OEE value of the personnel by 1.5-2 times. Before the OEE value of the operator, we need to make a good distinction between operator and machine. In other words, if your machine uses the human factor at a minimum level, if the personnel only stand at the machine during the shift and intervene very little, there is no personnel/operator OEE value here. This is because the operator has become a part of the machine and has little or no chance to use initiative. But if you are talking about, for example, manual labor, assembly, manual packaging, the staff has replaced the machine.

Before we talk about measuring and maximizing the OEE of a personnel, let's look at how many different operator-machine combinations there are on the shop floor. There are 3 types of situations: 1) 1 machine-1 operator situation (machine enabled): This is the category where OEE improvements can be made the least. This is because the machine is running continuously throughout the shift and the operator's contribution is limited. The operator is at the machine only for control purposes. In this type of process, it is only necessary to apply Operator OEE analysis if the worker causes the machine to stop for a long time. 2) 1 machine-1 operator situation (Operator active): Almost all of the contribution to production is made by the operator. Operator OEE value is essential in these operations such as assembly, packaging, manual labor. The way to make improvements in such processes is either to compare several operators doing the same job or to compare the OEE values of the same operator on different days. 3) 1 machine-n operator situation: This is the category where we will focus on maximizing OEE values. This category is the most open to comparisons and improvements, because the machine is the same and the operators are different.

The only way to compare productivity on the production floor is if the conditions are the same. That is, you can compare a worker on the 08:00 - 16:00 shift with a worker on the same shift. Values such as hunger, sleep deprivation, fatigue will show you different values between the two workers. The only way to compare correctly is to compare workers working on the same day, at the same time, doing the same job, working on the same machine. You can make this comparison manually, or panels that do Production Data Collection can do it. As soon as the shift starts, summary data about the products produced, the materials used and the workers whose stop-work times are recorded are formed as shown in the picture below. Comparison happens in two ways: 1) Comparison of working hours: Values such as how many hours the worker worked during the shift, how many solid parts he/she produced and whether he/she exceeded the production capacity constitute the OEE value. 

Andon Pano, Since it is still at the beginning of a shift, the values are very low. Assume that the OEE value of the machine where two workers work throughout the shift is 70. Let's assume that the OEE values calculated on an operator basis are 90 for the first operator and 50 for the second operator. 70 is a good figure for the machine, but there is a significant difference between the contributions of the workers to this figure. When we look at the availability, performance and quality values that make up the second worker's OEE value of 50, you will see that at least one of them is very low. This difference in one shift causes large fluctuations in the monthly values of the entire shop floor. In this example, the number of products produced by the workers may be the same, but the first one reached the product figure in 4 hours of work, while the second worker reached this figure in perhaps 3 hours and 20 minutes of work. It may look good that he produced the same amount in a short time, but one has to question where the 40 minutes of lost work went. 2) Comparison of downtimes: How much of the shift time workers cause the machine to be idle is possible by comparing downtime. Comparing the average downtime of two workers during a tea break, lunch break or waiting for raw materials and taking measures by analyzing the reasons increases OEE values on a factory basis.The way to compare productivity in the production area is only possible if the conditions are the same. That is, you can only compare a staff on the 08:00 - 16:00 shift with a staff on the same shift. Values such as hunger, sleep deprivation, fatigue will show you different values between the two workers. The only way to compare correctly is to compare workers working on the same day, at the same time, doing the same job, working on the same machine. You can make this comparison manually, or panels that do Production Data Collection can do it. As soon as the shift starts, summary data about the products produced, the materials used and the workers whose stop-work times are recorded are formed as shown in the picture below. Comparison happens in two ways: 1) Comparison of working hours: Values such as how many hours the worker worked during the shift, how many solid parts he/she produced and whether he/she exceeded the production capacity constitute the OEE value.