OEE and equipment commissioning
March 30, 2009 by adrianpask
Are you thinking about investing in new production line equipment?
Would you like to avoid having your OEE demolished in the process?
Here are our 5 top tips for minimising the length of time that your line is down for the install:
1. Agree to use automated electronic measures to sign off the new equipment - most equipment suppliers we meet are very happy to sign off large projects using tick sheets and manual observation both of which are subject to significant errors. Use PLC data for the commissioning exercise - when/should the OEM argue that the numbers are incorrect at least you know that their PLC code is also incorrect!
2. Agree the range of performance metrics well in advance including a total line metric for the trial.
3. The industry standards are Mechanical Efficiency and Running Speed. We would also recommend insisting on: Mean Time Between Failure, Mean Time To Recover, OEE (Availability, Performance, Quality), and Loss to Critical/bottleneck Machine.
4. XL800 systems are extremely useful for signing off new equipment as they can be installed in a matter of hours with a completely standard setup - just bolt it on, plug it in, run the machine, and there’s your sign-off data generated completely automatically.
5. Make sure you consider the line control - we’ve seen many installations in which new equipment is installed with only the absolute minimum line control adjustments. Typically this can kill as much as 5% of your total line efficiency. Very shortly we will post our Line Control philosophy to support you here.
We’ve been involved in the commisioning of everything from individual machine upgrade to full multi-million pound production lines and hope that these simple tips help you with your install.
Incidentally i’ve just spotted this blog which also has a great post on this topic: Click Here
Jidoka: Autonomation
January 15, 2009 by adrianpask
Jidoka is a term taken from The Toyota Production System and Lean Manufacturing that effectively means “intelligent automation” or “automation with a human touch”.
The purposes of jidoka are:
- To increase OEE by reducing waste
- To reduce the production of quality-inferior products
- To prevent damage to machines by causing automatic stops
- To enable your operators to focus on tasks other than just running machines
In practice Jidoka is a form of automation which prevents the production of defective products through some intelligent automation. Primarily Jidoka is a quality control process that has 4 elements:
- Detect the abnormality
- Stop
- Fix the machine or issue
- Investigate the root cause and fix
An example of Jidoka in action might be an inline quality detection system checking fill heights/weights:
- You produce a low fill - it is detected and no action is taken
- You produce 10 low fills in a minute - an alarm is sounded but no action is taken
- You produce 15 low fills in a minute - the filler is automatically stopped and an error message raised on your andon system
- With the line stopped your operator investigates the cause of the stoppage and makes a fix
In this process operators traditionally have the ability to make only very minimal tweaks to the production process settings, the majority of control is automated.
In this way applying Jidoka will help improve your OEE by increasing your Quality %.
More sophisticated versions of Jidoka can include production line control on automated continuous flow production lines. On a continuous flow line with good control, each machine will start, stop, and change speed automatically to maximise output without operator intervention. To find out more about production line control read our page here: http://oeejourney.optimumfx.com/2008/12/02/optimising-line-control/
Find out more:
Jidoka: On the Toyota website.
This jidoka website makes a great diffentiation between Autonomation and automation:
Automation is focused on labor reduction. Autonomation (Jidoka) is focused on quality improvement, and the independence of the man from the process.
Automation increases technicality, Autonomation reduces technicality. This allows skill levels to be lower in similar processes when comparing East to West. Another cost reducer!
Optimising Line Control
December 2, 2008 by samirshah
We believe that ineffective line control is THE HIDDEN OEE Waste! By optimising your line control you will be able to increase your performance (OEE) by up to 7%!
- Do you operate in an industry that requires filling of some sort of containers like bottles, cans, bags, etc?
- Do you have continuous flow production lines with conveyor systems between the machines?
- Do you feel that there is something not quite right with the configuration of the lines and there is scope of making the lines run a lot smoother?
If you answer yes to the questions above…..then read on
What do we mean by line control?
On continuous flow production lines, typical found in FMCG environments, there are broadly 2 types of production line configuration; block and accumulation.
Block production lines operate with most machines running at the same speed. Typically block lines run with very little conveyor space between the machines (often single track). Therefore a stop on any of the blocked machines quickly or instantly causes a direct loss of performance (OEE) for the line.
Machines are typically controlled through linking the PLC controls to change speeds/stop automatically for the entire line.
Accumulation production lines, typically food related such as Coca-Cola bottling, Crisp packaging and food packaging operate with individual machines linked with large amounts of conveyor space and generally take up a lot of factory space. Typically the machines in an accumulation line have the capability of running at variable speeds, and will normally have one machine (or one block of machines) which runs the slowest; we call this the bottleneck or ‘critical’ machine. The Performance (OEE) of this line is determined by the amount of time that we’re able to keep the critical machine running at its rated speed.
Assuming good line balance and control, the accumulation minimises the impact of minor stops on all machines other than the critical machine
Machines are typically controlled by conveyor-based sensors with little direct interaction between the machines.
Line control or line philosophy is the way in which machines are stopped / started in response to changing conditions on the line. E.g. Stopping in build back when a machine downstream stops, stopping in lack when a machine upstream stops.
Have you ever wondered WHY on your production line…..
- the conveyors are running almost full all the time
- the machines on the line stop and start from no apparent reason i.e. there has been no fault or blockage upstream or downstream of the machine
- when there is a fault downstream, it almost immediately stops the critical or constraint machine although there is plenty of accumulation conveyors in between
- when there has been a stop downstream, it takes a long time for the critical machine to start up again
- the machines downstream of the critical machine are always ‘hunting for product’ i.e. either running flat out or not at all
- when the machine stops due to a build back situation, the operator has to start the machine up again and this always causes a delay on starting up again
Would you like to see more of the following happen…..
- All equipment on the line runs in automatic with no manual intervention required
- In normal condition the line speed is matched to the speed of the critical machine
- Minor stops on machines upstream or downstream do not affect the critical machine
- Extended stops affect the critical machine for a minimum period
- Critical machine starts almost instantaneously as the machines downstream after a build back situation
…..this is our vision of perfect flow and it is possible to get as close to this philosophy as you want
At OptimumFX, we have perfected a way of optimising the Line Control philosophy of an automated production line by using what we call the ‘5 Levels of control for automated flow lines’. This includes looking at (not limited to) the following concepts:
- Look at automating all machines on the line, so that machines automatically stop and start during lack or build back situations requiring no manual intervention and the machine speeds are automatically set requiring no manual adjustment
- The conveyor speeds are adjusted so that in normal conditions they are running mostly empty maximising the dynamic accumulation space
- By adjusting lack and build back sensors the conveyor space is maximised
- Link the machines together so that speeds of all the machines on the line are matched to the critical machine during normal conditions preventing wear on machines due to sudden stop / starts
- On restart after stoppages ensure that the machines downstream have sufficient over speed capability, this enables clearing of the accumulation conveyors quicker and starts the critical machine as quickly as possible
- Look at maximising the time before the critical machine stops when there is a fault downstream and minimising the time before the critical machine starts up again when the fault is repaired
We have developed a comprehensive method of auditing the production line that will identify what needs to be changed to achieve the vision of perfect flow. This is based on prioritising the actions that will give you the greatest benefit. Give us a call and we will be more than happy to help you achieve this!
