Bottlenecks in your production environment don’t have to be an everyday occurrence! As we could talk for days about how bottlenecks occur, for the sake of this blog we are going to only discuss the top 4.
So why are bottlenecks so bad? Well, within a manufacturing process, they increase production times that essentially drive up production costs. Which cost is the number one metric every manufacturer worldwide is trying to decrease! However, bottlenecks can be avoided by proactively addressing each one with a Manufacturing Execution System (MES).
Now let’s look at the causes and how we can address each one with an MES.
1. Changes in the Process (new revisions of parts, added or removed parts, new barcode, new process setup)
A change within a process set up often require coordinated changes to machine controls (e.g. adding a part present sensor) and some do not (e.g. new color code), but in all cases, with a MES in place, a manufacturer can configure the system to send correct process setup for all content used in an operation.
MES also prohibits unknown content to send process setup values; usually missing configuration is an error that stops the operation from proceeding (and building incorrect parts).
2. Equipment/Machine Issues (poke-yoke or color sensor failure, process failure)
Eventually sensors do fail and cause bottlenecks due to the time it takes to get all sensors “reactivated” so the equipment can cycle. This delay appears as part of the operation’s cycle time, but it may take a while to zero-in on the exact cause of delay.
MES can use the same SPC techniques it uses for operation cycle time to track these inter-step times. For example, a sudden change in the “Operation 2 Cycle Start” time can indicate a problem with the equipment (sensor failure) or the content (color variation causes color sensor to “fail”).
Equipment that produces failing results is a serious problem, and the MES must not allow downstream use of parts that have failed in previous operations. An important consideration here is the proper handling of failed parts; the operator must be able to quarantine these so they are not used downstream.
3. Operator Issues (not trained, pathological behavior)
A new operator may lengthen all steps of the operation’s cycle time, because of the learning curve. Or an unmotivated operator may actively try to “trick” the system and otherwise cause bottlenecks.
As an unmotivated operator may allow failed parts to be put downstream, a MES identifies failed parts at the end of each cycle to ensure all failed parts are removed from production. However, sometimes an operator can (or is required to) produce parts successfully, but does not record any results. This can happen when:
- The MES is turned off or purposely subverted
- Network communication issues (with process equipment)
- Operator out-of-sync with process/MES
- Equipment is operated with the MES bypassed
Depending on the conditions, the operator may not realize they are even passing un-tracked parts to downstream operations….This is a “sneaky” problem, because it manifests itself downstream of the operation causing the bottleneck. So how can you avoid this?
A comprehensive MES always verifies previous operations succeeded, and this procedure now fails at the downstream operation, causing a bottleneck.
Here the MES can watch the result stream of all operations, and send alerts when validation failures occur repeatedly. More importantly, these alerts should identify the “real” culprit of the bottleneck: the previous operation where the “failures” originate. It is important to identify these situations quickly to avoid continued loss of cycle time and to correct operator behavior.
4. IT issues (hardware failure, admin, etc.)
The last bottleneck that we are going to address is IT. As IT staff is a critical component for minimizing downtime and MES use computer hardware and associated peripherals, it is critical that this equipment is in excellent running condition.
To minimize bottlenecks due to hardware, replacement parts must be readily available and easy to swap in and out. Ideally these are pre-configured (if necessary) so they will “just work”.
After the hardware, the network is the most critical piece of infrastructure, because every device involved in the process uses the network:
- Workstations and Servers
- Programmable Logic Controllers (PLCs)
- DC Drivers
- Test Equipment
- Printers
- Barcode Scanners
Planning maintenance activities (workstations, servers and networking gear) for off-production hours is a best practice, since many IT administration tasks are resource heavy, like backups and virus scans. Running these tasks during production hours can cause inadvertent downtime and bottlenecks because of reduced availability.
In summary, today’s manufacturers do have the capability to completely eliminate bottlenecks from their manufacturing process with a comprehensive manufacturing execution system in place. By enabling intelligent manufacturing best practices with MES solutions, manufacturers are reducing production times in turn reduce overall production costs.