Overall equipment effectiveness (OEE) – What’s the point?

Anyone who is accountable for improving manufacturing performance should be skeptical about OEE. Without an inquisitive mind setting thoughtful goals, the outcome will likely not be success. In truth, OEE is a scoreboard and we are all playing the game. Every player and spectator needs to hold the organization and the officiating to account and make sure the game is a true exercise in improving performance. The reality is that countless conversations about how the game is played and how the matrix of statistics relates to the players will make a more successful enterprise.

It easy to get caught up in some academic implementation of OEE and lose the purpose of the endeavor. Let’s not do this. When asked to establish OEE in an organization, a large sum of money is often spent on expensive software and the expectation is a once-and-done implementation. Software will be important in achieving a practical implementation of OEE; however by itself, OEE is not software. OEE can be done with some worksheets and a clipboard. Everyone who is accountable, in regards to performance on the factory floor, needs to understand the numbers – that’s the point. When the numbers seem unfair or irrelevant to the model that represents the baseline performance, users should be complaining about the software and changes should be made.

I would like to challenge you to come up with a simple example that will allow you to integrate the concept of OEE. For example, I will track something simple.

Let’s assume I am a machine, outputting keystrokes. My output is determined by how many keystrokes I produce minute while I am working. I am scheduled to work 8:00 to 5:00, five days a week. For simplicity sake, let’s say I will type all day long and be fully loaded (9 hrs.). I take an hour lunch and random amount of distractions take me away from the keyboard and effect the availability (5 hrs. at keyboard) of keystroking. I have a skill that has some level regarding hitting keys, a possible performance (WPM 22) expectation of so many words per minute I may produce. I may not produce a quality (3 out of 22) results with all this keystroking so good vs. bad content needs to be determined.

This below example shows the simple OEE web application OEE calculation based on the above data

I was not typing for the whole shift, so I had 5/8 (0.625) of the day available in at 5 out of 8 hours. Which is my loading for the day minus my hour lunch break.

I could have produced 22 (WPM) * 5 hrs. 5700 total words. I fell short at 5000. Making my performance less than 100%.

I produced bad quality words upon review. This is separate from performance and reflects only ratio of good verses total pieces.

OEE Web Application Demo

What’s the point? This is really just more data. To produce meaningful information we need to know what the baseline is. Basically, what the history is. Just like a baseball statistics like, Times at Bat, Hits, and Bases Run it gives an expectation to all the stakeholders we can mark improvement against. It give us data goes deeper than what is currently happening, incorporating the history of data by tracking stats. Creatively applying knowledge to the way the game is played based on current conditions is the point. Without the critical input and the ability to change the current trajectory or events this exercise would be somewhat meaningless. In the end the players need to standup and want to play ball.

There’s plenty to argue and disagree about in the above example. But, by having these arguments we are setting our focus on overall performance.

1. Who to say that my maximum words should be set at 22 WPM. That rate is not all that impressive. Also, some words are harder than others? Setting performance expectations too low may inflate numbers. We should never hit 100%.

2. One could argue that someone should have kept typing on my keyboard over lunch if I wasn’t typing. Maybe I did type over lunch but counted me break anyway. Under stating availability by making claims of scheduled downtime can inflate numbers as well.

3. How useful are these words are they quality words? This assumption can be hard prove. Overlooking bad quality could inflate OEE numbers. If I sent these words to a publisher and they were all rejected my true cost could be much more than doubled if I need to replace the words.

 

Posted in IT Information Tech.

Uptime Downtime Reporting with SQL Server and Ingnition OPC UA

In order to use SQL server for Up-time, Down-time and Production Reporting, data needs to be collected from the machine operation.  The OPC standard allows for the collection of this data from a multitude of industrial devices – too numerous to mention.   

Inductive Automation, used in this proposal, is one of the few products developed to use SQL for its base for storing the information collected from the machines.  The term OPC (stands for OLE for Process Control) is dated and esoteric.  In short, the newer versions of the standard don’t even rely on the old Microsoft technology OLE (Object Linking and Embedding).

 Basic Arcitechture

The Ignition server would reside on your Dell Power Edge as a virtual instance of Windows Server 2012 Web Edition.  It would run SQL Server Express Advanced Edition with reporting. 

Advantages

  • Everything runs from a central server
  • No client and development software is pushed from web browsers
  • SQL server is at the core of TAG addressing to your devices
  • Platform independent software prevents need to upgrade OS platform
  • Modern design environment makes simple changes possible

* In contrast many legacy market leaders require running Windows in XP mode to have clients on 64x computers.  This is a kluge of a work around that drastically impacts usability and should not be considered compatibility with 64x versions of Windows by Microsoft’s standards. 

Application Design

The Ignition server would have the following functionality

  • Centralize data on production and machine utilization
  • Keep audit logs of machine settings / changes
  • Provide reporting engine for customized reports
  • Provide development environment for up-time down-time reporting

Cause reporting can be accessed via any operator interface to the PLC and stored in the Ignition server. 

Ignition sells MES solutions for OEE (Overall Operational Efficiency) – this may be desired down the road.   Basic up-time down-time reporting is a good first step to reaching goals with the OEE practice, if desired.

Posted in IT Information Tech.

Using Refurbished Enterprise Class Server for Economical High Reliability Server using VMWare ESXi

Purpose:
Consumer grade computers proved to be too unreliable for mission critical server operation. The objective is to upscale the computer infrastructure to enterprise class hardware, allowing us to implement reliable RAID 5 and system failover. This is for a small user base that requires high quality service. Even simple SATA RAID level 2 systems proved to be unreliable delivered with motherboard provided controllers. These are proven reliable controls that should work without issue for many years more than this equipment should remain viable. Hopefully SSD technology will render this platform obsolete and cost ineffective within a few years.

Approach:
Purchase late model Dell PowerEdge 2950 III servers that are coming off lease. We integrated 2 ESXi servers on Dell 2950s one has 16GB and the second 32GB. Upgrade the hard drives to 1T SATA enterprise class drives.
The SAS hard drives were replaced with 1T Enterprise Western Digital drives (WD1002FBYS). Both computers had the batteries replaced, after some hardship with RAID errors.

Lessons Learned:
1. Buy only servers that have PERC 6/i controllers maybe the PERC 5 is ok who wants to find out.
2. Replace the battery, the RAID array will fault if the battery is dead. Intermittent problems will occur if the battery is marginal.
3. Use Enterprise drives that are less than 2 Terabytes.
4. ESXi needs to be licensed to have backup strategy
5. Veeam is an excellent backup/migration product

Outcome:
This project was successful. I would keep the same approach if I were starting again today in 2013. The RAID arrays will write at ~80MBS under ideal conditions. The servers are running AD, VOIP, Exchange, Ubuntu PHP Web applications as well as IIS ASP applications. The server room is much cool and more efficient now that the old Pentium class servers are gone. The backup and migration strategy has realty simplified. It was prudent to invest in software over hardware. Future migrations to new server will be effortless with the virtualized servers. One of the advantages to this approach is that you can restore server between the ESXi boxes to test the restoration. Also, the restoration for all OS disruptions is the same. The quality of the 2008 era enterprise equipment is impressive. The price is extremely low. Server centers liquidate 10, 100s if not 1000s of theses server at one time overloading the market. We purchased these for well under ~$500.00.

Posted in IT Information Tech.