Getting Started with OEE (Overall Equipment Effectiveness)

OEE

Aug 27

If you’ve attended a conference anytime since 2015, you’ve probably seen a number of MES Lite, OEE Lite, OEE Accelarator, MES Starter Kits, or a branded variation of the annual buzzword. These products are often a pre-built set of screens and components promising to give you OEE data in “a fraction of the time”.

If you have worked at all with Sepasoft’s MES platform—and worked for any of the companies that implemented their MES modules back in the Version 1.0 days—you also probably saw the screens developed by one of their former sales engineers. IYKYK

While it’s not bad to have these tools, they’re usually only handling the low hanging fruit of an OEE implementation. Building the production models, configuring tags, and getting data into the hands of the people who want to see it is the easy part of an OEE implementation. The hard parts of a successful OEE rollout (and which also require the most work) are: finding the data in the first place, getting access to it, and validating that it is correct.

Chart illustrating OEE and how it relates to the bottom line - how each area of the blog post below contributes to the total cost of lost production

OEE: Show Me The Data!

The first step toward OEE success is making the data available. You must be able to track the following:

Downtime Vs. Uptime

Reasons why is the machine down (numeric reason codes are the easiest to work with: 0 stopped, 1 running, 2 starved, 3 blocked, etc.)
Schedule (should the machine be running right now or not?)
- Which work orders should run on this machine, and when?
Changeover Duration
- Will depend on a material/product type

Machine Throughput

Machine throughput depends on the products the machine is producing. Knowing what you are making—and when—is absolutely critical.

Standard Rate (How many units can this machine produce per period of time?)
How many units did this machine make per period of time?

Quality

How many units were started?
How many units were bad or required rework?
How many units were good?

Common hurdles for getting the above data: no downtime reasons programmed into the PLC—or no PLC to communicate with, not knowing the standard rates per machine/product type, not having a way to track what is started on the machine vs. what is finished, and not having a direct way to measure quality losses.

Thankfully, all of these hurdles are relatively easy for us to overcome with additional hardware, software, or integration with other systems where the data already resides. Corso Systems excels with these tasks, schedule a short, no obligations intro call with Cody Johnson in sales to get started ASAP.

Integrating the Data with the OEE Backend

Once you have the data in the PLC, we can tie it into the OEE backend. However, the data might not be directly available in the PLC—or there might not be an easy way to get it into the PLC in the first place.

Difficult Data Source Examples:

In ERP systems:
- Material/Product Codes
- Work Orders/Schedule
- Standard Rates for various products
- Changeover times
In databases or manually entered:
- Scrap/Rework counts
- Downtime Reason Mapping

For data like material codes, we can develop a script to read in all of the codes from the system on a periodic basis. As new materials are added to the system, they will get picked up without causing issues the first time they’re run on the line. As work orders start in the MES system, you can populate these values either in the PLC or in memory tags in your SCADA platform—then pull them into the OEE engine to perform the proper calculations.

We will need to run queries for scrap/rework counts, downtime reason mapping, and other items stored in databases. The queries will run when the production runs are starting in order to pull in the relevant data and populate it either in the PLC or in memory tags for the OEE engine.

The most complicated item on the list is scrap/rework counts. Depending on the process, collecting this data will require an end of day roll-up to bring it into the system. It can also happen at the end of the production run if there is a live tally during the run. Both of these options will generally require coding to make the proper adjustments in the OEE calculation engine. If the scrap is not yet accounted for, it will also obviously affect OEE depending on the time of day you look at the information.

Validating the Data

Validation is the most time consuming and involved part of an OEE project. Subject matter experts on the customer side will almost always need to be involved to verify that plant floor activities are correctly reflected in the data.

They will need to understand:

Each downtime reason
How parts are tested to ensure compliance with specs or if they are scrap
The production schedule
What they would expect to see based on the OEE engine vs. reality

Validation extends to the data—as well as how the data is collected. This includes finding any production count duplications along the way, and if the schedule is operating correctly for the right standard rates across the production line.

Even if everyone is doing their job properly, there will still likely be a decent amount of re-validation. The issues at hand are often not understood until the system is in place and will need to be adjusted then re-validated.

Ready to Get Started with OEE?

We say that an OEE Starter Kit only impacts low hanging fruit because none of the actual work detailed above is included. Even with a starter kit, the system functions still need to happen at the screen level—and most of the screens are already using standard components. Once everything is hooked up, they should just work, and the major changes will be formatting, style, and format. But, you need to have the data in a usable form first. Corso Systems has never found that the task of creating OEE screens have caused significant delays on an OEE project. Design changes are a relatively easy to implement and resolve. The screens—from a starter kit or otherwise—can only display the data we put into them, and the hard part is making sure the correct data is collected and stored in the first place.

The next time you find yourself asking for pre-made screens and templates to speed up the deployment of your OEE project, first stop and ask your team if you have all of the right data in place. If you have all the right information on Day One, then implementing your OEE project will go a whole lot more smoothly, with or without a starter kit. Corso Systems can help you every step of the way.