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Throughput rate is a parameter for the product from the first process to the last process. It can understand the ability of the product to reach the finished product under all processes in the production process. It is a parameter that reflects the quality control ability of the enterprise. In an ability to meet customer product requirements, the higher the pass-through rate, the stronger the ability. China wholesale high precision custom black anodized aluminum tubing

Throughput Concept

First Pass Yield (FPY) is an indicator to measure the quality level of the production line, which is used to describe a certain condition of production quality, work quality or test quality. The specific meaning refers to the number of good products that pass all the tests for the first time in the production line with 100 sets of materials. Therefore, products that pass the test after rework or repair on the production line will not be included in the calculation of the pass-through rate.

Throughput calculation formula

There are the following forms (depending on production sampling):

Product straight-through rate = (number of pieces in the process – (number of rework + number of repairs + number of returns)) / number of process pieces * 100%;
Straight-through rate = (pass-through qualified number/total investment) * 100%.

Thru rate in practice

The above definition has its difficulties in practical calculation, because the size of the input batch is different, and the date of batch completion is uncertain, so the actual calculation adopts the following calculation formula:

FPY= p1 x p2 xp3 … where p1, p2, p3, etc. are the first yield of each test station on the production line.

Through this formula, we can know the timely production line through rate. Sometimes this pass rate is more representative of the true quality level of the production line than the yield rate. China wholesale high precision custom black anodized aluminum tubing

Other Meanings of Through Rate

In addition to the meanings listed above, pass rate can also be extended to descriptions such as one-time completion of exam or test results.

Several questions about the pass rate

To improve product and service quality, process quality must be improved. To do this, the process must be measured and the process understood.

Six Sigma usually uses the following three indicators for the output of the process: Throughput yield, Rolled throughput yield and Normalized yield. China wholesale high precision custom black anodized aluminum tubing

1 The throughput rate is an indicator to measure the output rate of the whole process?

A process is an activity or set of activities that utilizes resources to convert inputs into outputs. If an activity also defines its input and output, then such an activity is called “job”, and it is also a small process. The whole big process, also called the process, can be regarded as several tasks and composed of small processes.

Throughput yield is a measure of process output, which indicates the probability that a product can pass a job without defects. Rolled Throughput Yield (RTY) is a measure of the probability that a product can pass through the entire process without defects. It is also one of the indicators of productivity. Let us also illustrate with an example.

Assume that the entire process consists of 5 jobs. Their pass rates are 0.95, 0.93, 0.98, 0.98, 0.94, respectively. Then, the Rolled Throughput Yield of the whole process is the product of 5 pass rates.

RTY = 0.98X0.93X0.95X0.98X0.94= 0.7976
It means that about 80% of the products can pass through the entire process of these 5 jobs without defects. China wholesale high precision custom black anodized aluminum tubing

2 What is the difference between the pass rate and the traditional measurement method?

Traditionally, the yield rate of the entire process is measured by the one-time pass rate at the final stage of inspection. The difference between the two is:
A. Similar to the pass rate and the first pass rate, the pass rate reflects the quality of the process more than the final pass rate. See the blog post “Pass Rate – One of the Process Output Indicators”.
B. The one-time pass rate in the final stage inspection cannot reflect the quality of the previous work, but the pass-through rate can.
C. The pass-through rate can provide more accurate information to leaders.
The pass rate can reflect the complexity of the product. In addition to reflecting the complexity of the product, the pass-through rate can also reflect the complexity of the process. It can be seen from the calculation formula. The pass-through rate can be improved if the number of jobs in the process is reduced. The traditional measurement method is unable to reflect.
Indicators such as pass rate, DPU, DPO, DPMO and Sigma value of Six Sigma management are applicable to both measurement and count data. Because, the defect of Six Sigma management is directly measured according to customer requirements, which is different from the traditional measurement method, first determine the process capability, and then calculate the process capability index CP, Cpk, to reflect the process capability to meet customer requirements. Not applicable to count data.
The traditional measurement method is only the result of the measurement process, which is the measurement of the past; while the pass rate and sigma value can measure the ability of the process, which gives a probability and statistical value. These data can be used to predict future outcomes of the process if the conditions of the future process do not change substantially. Please see the introduction in the next section. China wholesale high precision custom black anodized aluminum tubing

There are other differences, which will be discussed further in conjunction with the introduction of other metrics.

3Why the pass rate and direct pass rate are not promoted?

People don’t know there is such a good method, and of course they won’t apply it.
The traditional method is simple and practical. The problem is, people tend to substitute convenience for right. They would rather do it and rework it later than take the time to get it right all at once. Six Sigma teaches people to work smartly without hard work. Six Sigma teaches people to work correctly, not just for convenience.
Habits. The habit of leadership is the key here. Some leaders do not study the inherent objective regularity of things, and only rely on intuition and subjective desire to direct. As long as it’s okay, what new things are there to learn? If you don’t measure it correctly, you don’t know how things are, let alone how to improve them. This is the fundamental reason why the energy consumption of our country, the same gross national product, is much higher than that of advanced countries.

Several major applications of through rate

Determine the nominal pass rate. When we know how many jobs there are in the whole process and what is the required pass rate RTY for the whole process, we can find the “nominal pass rate” of each job. It means that to achieve the pass rate target, the pass rate for each job should be no lower than the nominal pass rate. The calculation method of this nominal pass rate NTY is very simple, which is the k-th power of RTY. for example. China wholesale high precision custom black anodized aluminum tubing

For example, there is a process, which consists of 10 operations (it can also be called a process). According to past data, the pass-through rate of this process should reach 36.8%. The result of raising 36.8 to the tenth power is 0.9048670. That is, the average pass rate for each assignment should be no less than 0.905 to reach the RTY = 0.368 target. In this way, each job leader can be asked to calculate the pass rate of his own job and know which job should be improved.

Determine the feeding quantity N. When we know the RTY of the whole process, we can determine how much material should be started according to the following formula:
If all defects are reworkable, then,
Nr = 1 + (1-RTY)
If all defects cannot be reworked, but only scrapped, then,
Ns = 1/RTY.
An example is as follows: It is known that the pass-through rate is 0.70, then, if the defect can be reworked, the feeding quantity should be 1+(1-.70)=1.30. If the defect cannot be reworked, 1/0.70 = 1.43 is required. That means, if you want to get 100 pieces of products, if they are defective and can be reworked, you should submit 130 pieces, and if they cannot be reworked, you should submit 143 pieces of materials. If some can be reworked and some cannot, it is in between these two data.
Determine the working time budget. When we use activity-based costing to control the cost of activities, or when we are required to carry out the schedule, we can use RTY to budget and control the time of the operation. For example, we denote the standard working time of a job as Tb and the expected actual time as Ts. So, in the above example, a process has 10 jobs. China wholesale high precision custom black anodized aluminum tubing

RTY is 0.70. Suppose, Tb = 10 minutes per job. From an average point of view, the plan should be scheduled for 13 minutes. Correspondingly, the stock material and the quantity on the assembly line can be determined. Based on these, you can track the cost and schedule of jobs and processes. These reference data are not available using traditional measurement methods.

The pass rate and the pass rate can be easily calculated by using the negative number of DPU as an exponential function based on a natural number. Please refer to the relevant articles, and will not be further explained here. China wholesale high precision custom black anodized aluminum tubing