The pursuit of ever better OEE scores has become a focus for those in the food and beverage industry in recent years. It is becoming increasingly common on the plant floor to see screens overhanging each packaging line, displaying productivity figures for all to see. Many find that such an approach significantly improves productivity.

OEE itself, however, is not a conversation users routinely have with their machinery suppliers, with the focus instead tending to be on areas such as baseline speed, cycle times and overall performance. However, if machine builders can bear OEE in mind during a machine design, and subsequently demonstrate how their machine designs can contribute to improved OEE results, then they may give themselves an advantage.

Increased availability

The inbuilt diagnostics and monitoring capabilities in today’s automation equipment, such as Omron’s Sysmac control platform, offer opportunities for reducing or even all but eliminating unscheduled downtime. Inbuilt diagnostics can highlight problems before they become critical. These are systems that machine builders can easily build in as part of the machine design – without incurring additional costs.

Consider, for example, the operation time of an actuator or cylinder. With a simple teach operation, the controller can learn the ideal move times in both directions, and limits can be expressed – creating rules perhaps for an early warning, and an alarm if the actuator’s operation time falls outside of these rules, predicting a potential impending problem.

The same thinking could be applied to sensors on the production line. Each sensor will have its ideal working conditions, but vibration can push it out of alignment, or a build-up of splatter could gradually impact on its operation. The control system can monitor the sensor’s performance – with limits set to trigger alarms as the output drifts towards tolerance limits – giving maintenance staff time to investigate the problem before it becomes an issue.

The machine controller can flag these warnings and alarms on an HMI local to the machine or inform engineers remotely, giving operators time to look at the device and to take appropriate action before failures occur. 

Changeover time

A further benefit to be derived from automation is being able to demonstrate to a customer, for example, how changeover times from one product size or packaging style to another could be reduced.

‘One push configuration’ is now a standard feature in automation technologies such as Omron’s Sysmac platform, principally because a whole range of products can be integrated over a single network protocol. Omron has standardised on EtherCAT as the ideal, high speed machinery communications network and programmed and set up from a single, unified software environment. This brings a single point of access to the configuration of the likes of servos, vision systems, sensors, temperature controllers, PLCs, drives and higher level databases.

Once the operator can configure the entire line from a single push button operation on an HMI, product changeover times are dramatically shortened.

Minimising downtime

Even the most reliable of equipment can fail unexpectedly. If the faulty part is a complex piece of electrical equipment that may have incurred significant programming effort, then the end user could face substantial downtime. Mounting and cabling a new variable speed drive, for example, is nothing compared to the time taken to set it up and program its parameters.

Machine builders can offer the benefits of backup/restore functionality, perhaps with critical program settings and parameters stored on an SD card. Many Omron Sysmac components such as controllers and HMIs come with SD card slots, and components that don’t have SD card slots can have their settings saved to SD card via a networked HMI for example.

Potentially this could help an end user get a machine back up and running without needing to call on engineering support from the machine builder.

Importantly, none of the features which can help to increase machine availability have to be a challenge for the machine builder to implement. For example, Omron has addressed the requirements for teach activation, monitoring, pre-alarm warnings and alarms with a suite of new Function Blocks within the Sysmac control platform. This standard library of function blocks comes at no extra cost as part of the Sysmac Studio programming environment.

The technology ensures that information is delivered to the right person – in the user’s maintenance team or with the machine builder’s support personnel – at the right time, enabling action to be taken. It enables preventative maintenance during scheduled downtime rather than reactive maintenance during unscheduled downtime.

Further, the information gleaned from any impending fault alarms is not just of use to the end user in the moment; archived in higher level databases, it can provide useful trending information that can show how a machine performs over time, and can provide a basis for continuous improvement.