Picture a factory, running at world-class OEE – all processes and services run at peak performance, there are no wastes and no unplanned breakdowns. What we at Evocon see is that in reality, at most manufacturing companies, actual conditions are not perfect.
Process assets like machines, tooling, and other equipment need maintenance, machines unexpectedly break down, and performance varies. Additionally, there are unknown changes that create slowdowns. Even human resources go through periods of low output. Sometimes a person changes the quality of the product and won’t even notice.
To stay aware of how your processes are doing and achieve OEE targets that are world-class, you need an OEE software to monitor data in real-time. In doing so, you can react to issues and improve things faster.
OEE system – a tool to monitor your production process
OEE or Overall Equipment Effectiveness is not a new concept. Seiichi Nakajima, the originator of Total Productive Maintenance in the 1960’s, created the technique for evaluating the manufacturing system. The process (OEE) includes three important goals, and the basic premise is to calculate an operating efficiency. And the OEE calculation is based on machine uptime (availability), the speed of the process (performance), and the output quality (yield). Or in other words, an operational machine running at optimum speed with acceptable quality output.
Businesses today rally around new and emerging technologies as the latest IT solutions give us faster (real-time) data collection. There is also rising popularity of Industry 4.0 style factories where there is a need to monitor process conditions in real-time. And this is where automated OEE comes in.
It sounds simple, and the math is easy. But too often we see at Evocon how managers and improvement leaders start an implementation, then after a while stop. The info flow stops, and the tracking of data fails. They have live OEE data but are faced with the questions “Now what?”.
The good news is there are ways to avoid the common OEE mistakes and achieve world-class OEE in all your factories. It requires us to take on better OEE implementation tactics. We must standardise our procedures and use people to help be more successful.
Standardise implementation and achieve world-class OEE
Here are a few frequently asked questions about OEE that we get at Evocon:
- What is the value-add if we compare one machine or process to another?
- What is the benefit of linking several factories located in various parts of the world?
- Why link the OEE software if my processes are different?
These questions assume all processes are different. If a business has the same machines and products running everywhere, the similarities are easy to explain. But what about unlike product lines? Different technologies? Dissimilar materials running in many separate sites? Are these processes the same?
Different manufacturing processes, same OEE
The OEE calculation is easy to apply to different machines and processes. Because, even when we run different types of products, every process is the same from the OEE standpoint.
Materials and products may differ. Technologies can be different. But, regarding the process, these are just the ins and outs. Every production process needs a machine. Every process must have a type of material (and information) that converts to a sellable form. And every process has people involved.
The OEE estimate needs to know:
- Is the machine running? Yes or no, and for how long in a period?
- Is the process (machine/material/person) operating at the expected rate?
- Is the output of the process acceptable?
When we look at the process this way, it becomes easy to compare a wood processing line to a food packaging line. These are two very different manufacturing settings that have the same measures of process operation through OEE.
Standardising machine breakdown causes
To achieve world-class OEE in all your factories, we must study definitions and terminology as well. For example, how are machine breakdown reasons defined in your process?
Some might consider machine breakdown to be any time the machine is not running. This definition does not take into consideration the effects of scheduled downtime. Events such as when the plant shuts down for maintenance. Those times when the schedule does not require the machine to run, etc.
The best approach is to make a standard definition of these states. Each should remain specific for each OEE usage. If the team defines unscheduled or unplanned machine downtime as the only metric they track, then each factory, process, and production line must do the same.
Other key elements to keep in mind regarding OEE and production downtime are the use of standard Total Productive Maintenance (TPM) breakdown causes. If the machine in one area goes down due to a “control unit override,” and the machine in somewhere else has an “electrical surge shut down.” Are these the same? They might be the same, but what if we do not change the label? We may never know if the events are common. That is why you must invest time and get things right when you want to achieve a world-class OEE in all your factories.
Defining process elements
In addition to standardising machine breakdowns, it is also important to have a unified understanding of the different process elements. It helps avoid many of the common failures and misunderstanding when implementing OEE in multiple factories at once.
Here’s a list of standard definitions that you can use:
- Breakdowns – either a complete loss or reduction in function.
- Slowdowns and stops – differ (from machine breakdowns) based on time and impact.
- Setups – switching from one product or service to the next (includes time to get the process up to speed).
- The process runs too fast or too slow – loss occurs when running at differing speeds than what is normal. Too slow, the output is low. Too fast, a strain of the process might cause an adverse effect on other parts of the process.
- Startup – when the process begins, it takes time to “ramp-up” the process.
One of the main benefits of defining the process elements in a unified way is to gain awareness of routine. And it helps to look at all machines equally. This small effort of getting the definitions right is well worth the effort. As it helps you get your OEE implementation process running correctly right from the beginning.
Calculating OEE in a unified way
Standardized segments of OEE does not end with standardised breakdown reasons and common definitions for the production process. Another pitfall of poor implementation is non-specific calculations of efficiencies. Often, sister plants will have its “own way” of computing things.
Here is a scenario: A business wanted to know the turnaround rate on a maintenance order. The decision to measure the downtime of the process as a function of time from when the maintenance started working on the job until finished.
- Factory ‘A’: Start-time of the maintenance job begins when the maintenance team arrives at the machine, logs into the control unit, and starts the repairs. The order ends when the repair team logs out.
- Factory ‘B’: Start-time begins when the production line reports the breakdown. The order ends when the first good product comes off the line.
See the difference? Just restating the terms (breakdown reasons), and defining process elements for world-class OEE is not enough. The terms may be the same, but the calculations must also be equally defined. The best practice is to clearly define and implement the same approach across all locations of installation.
The benefits of standardised OEE
The overall objective for the implementation of OEE is to have a standardised basis of process performance measures.
The company wins in many ways when the operations teams can benchmark themselves and analyse set OEE targets. And a standardised approach goes a long way in helping you achieve a world-class OEE in all your factories. Regardless of what machines or production process you have.
The standardised approach of implementing OEE has many benefits, including:
- Overall process awareness within each location, at corporate offices, and satellite sites.
- More effective deployment of continuous improvement teams.
- Allocation of resources to the most valuable areas.
- Best practice sharing from line to line, and factory to factory.
- A decrease in overall production downtime.
- The realisation of spare capacity and the ability to maximise machine utilisation.
- Avoidance of excess capital expenditures.
- An overall improvement in operator engagement.
- Cross collaboration of TPM practices across plants in different parts of the world.
Each shop floor may differ. But the bottom line is that a standardised OEE implementation across a multinational business is the best practice.
The use of a standard OEE software such as Evocon offers a common way to visualise the production process. And it provides a universal language. The shared influence on the separated processes from a connected system allows managers to monitor the changes, in real-time, without the need to create new methods to measure and share results.
Make sure you read our “Case study: The benefits of a standardised OEE system“ so that you can start off in the right way and avoid the common pitfalls of a non-standardised OEE implementation.