Does anyone actually look at their daily equipment availability? Instead of using TEEP that is typically based on calendarized availability, looking at the Daily Equipment Effectiveness Performance of your operation may provide some interesting insights.
Working overtime due to material or equipment availability occurs many times. Unfortunately, we find that sometimes these very same machines are idle during the week.
A detailed explanation for calculating DEEP can be found in one of our earlier posts, “OEE, Downtime, and TEEP.” Understanding machine utilization patterns may provide greater insight into the actual versus planned operating pattern of your process.
Just something to invoke some thoughts for your operation and to perhaps identify another opportunity to improve performance.
We are currently offering our Excel OEE Spreadsheet Templates and example files at no charge. You can download our files from the ORANGE BOX on the sidebar titled “FREE DOWNLOADS” or click on the FREE Downloads Page. These files can be used as is and can be easily modified to suit many different manufacturing processes. There are no hidden files, formulas, or macros and no obligations for the services provided here.
We are often asked what companies (or types of companies) are using OEE as part of their daily operations. While our focus has been primarily in the automotive industry, we are highly encouraged by the level of integration deployed in the Semiconductor Industry. We have found an excellent article that describes how OEE among other metrics is being used to sustain and improve performance in the semiconductor industry.
Somehow it is not surprising to learn the semiconductor industry has established a high level of OEE integration in their operations. Perhaps this is the reason why electronics continue to improve at such a rapid pace in both technology and price.
The article clearly presents a concise hierarchy of metrics (including OEE) typically used in operations and includes their interactions and dependencies. The semiconductor industry serves as a great benchmark for OEE integration and how it is used as powerful tool to improve operations.
While we have reviewed some articles that describe OEE as an over rated metric, we believe that the proof of wisdom is in the result. The semiconductor industry is exemplary in this regard. It is clear that electronics industry “gets it”.
As we have mentioned in many of our previous posts, OEE should not be an isolated metric. While it can be assessed and reviewed independently, it is important to understand the effect on the system and organization as a whole.
We appreciate your feedback. Please feel free to leave us a comment or send us an e-mail with your suggestions to email@example.com
In this post we will present a simple method to calculate a truly weighted OEE, including weighted factors Availability, Performance, and Quality.
The QUICK weighted OEE method:
Recalling our original definition of OEE, we are measuring how effectively our planned production time (net available time) is used to make a quality (saleable) product. The weighted OEE then is the total time required to make a quality product divided by the total net available time.
From our examples in the “Calculating OEE” post, the following table summarizes the time required to produce quality products ONLY for machines A, B, and C:
Machine A: 365 minutes
Machine B: 318.75 minutes
Machine C: 254.34 minutes
The total time to produce good quality (saleable) products is 938.09 minutes.
The total net available time for the three machines is 1365 minutes (3 * 455 minutes).
The total weighted OEE for the 3 machines = 938.09 / 1365 = 68.72%
Calculating the Weighted Factors:
A similar process to the one described above can be applied to the individual factors. It stands to reason that when the individual factors are multiplied together that we should get the same result. We will use this to check our answer.
Availability measures machine uptime efficiency. The definition applied to an individual process also applies to the total of all the machines. Availability is calculated using the formula:
Availability: Net Operating Time / Net Available Time
From our examples in the “Calculating OEE” post, the following table summarizes the Net Operating Times for machines A, B, and C:
Machine A: 423 minutes
Machine B: 437 minutes
Machine C: 433 minutes
The total Net Operating Time = 1293 minutes.
The total Net Available Time for the three machines is 1365 minutes (3 * 455 minutes).
The weighted AVAILABILITY for the 3 machines = 1293 / 1365 = 94.73%
Performance measures machine operating time efficiency when compared to the “ideal” cycle or operating time. The definition applied to an individual process also applies to the total of all the machines. Performance is calculated using the formula:
Performance: Ideal Operating Time / Net Operating Time
From our examples in the “Calculating OEE” post, the following table summarizes the Ideal Operating Times for machines A, B, and C:
Machine A: 373.33 minutes
Machine B: 337.50 minutes
Machine C: 267.17 minutes
The total Ideal Operating Time to produce ALL parts = 978 minutes.
The total Net Operating Time for the three machines is 1293 minutes (See Availability Calculations Above).
The weighted PERFORMANCE for the 3 machines = 978 / 1293 = 75.64%
Quality measures how efficiently the “ideal” operating time is used to produce quality (saleable) products. Again, the definition applied to an individual process also applies to the total of all the machines. Quality is calculated using the formula:
Quality: Ideal Operating Time to Make Quality Parts / Ideal Operating Time
From our examples in the “Calculating OEE” post, the following table summarizes the Ideal Operating Time to produce Quality Parts ONLY for machines A, B, and C:
Machine A: 365.00 minutes
Machine B: 318.75 minutes
Machine C: 254.34 minutes
The total Ideal Operating Time for Good Parts = 938.09 minutes.
The total Ideal Operating Time to produce ALL parts for the three machines is 978 minutes (See Performance Calculations Above).
The weighted Quality for the 3 machines = 938.09 / 978.0 = 95.92%
Weighted OEE cross check:
Let’s compare the results. From the calculations above, the results are summarized as follows:
Weighted Availability: 94.73%
Weighted Performance: 75.64%
Weighted Quality: 95.92%
Now, we multiply the individual weighted OEE factors together:
OEE = 94.73% * 75.64% * 95.92% = 68.73%
You will see the result is the same as the Quick check introduced at the start of this post.
In our next post we will show you how to calculate the weighted factors for each individual process and introduce yet another way to confirm the weighted OEE calculation.
We have created a number of Excel spreadsheets that are immediately available for download from our FREE Downloads page or from the Free Downloads widget on the side bar. These spreadsheets can be modified as required for your application.
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