Find out how one specialty manufacturer minimized machine downtime by managing automation program changes

Is your plant protected against human error, equipment failure, etc.? Who is making changes to the automation devices in your plant? Where is the latest version of the device program? What changes have been made to your device programs? If any of these questions cannot be easily answered, your plant is at risk for downtime, product loss, safety hazards, security breaches, loss of intellectual property and more. The increased use of plant floor automation to achieve production goals has created a dependency on industrial programmable devices such as PLC, CNC, HMI, Robots and drives.  Many of these programs are changed as adjustments to variables and logic are needed to continue smooth operation, but these changes also put the plant at risk. What happens if someone makes a change to a program that results in undesired performance, or corrupts the program due to inadvertent changes? If there is no backup the result is costly downtime.

For example, take SWEP, part of the Dover Corporation, that experienced unplanned stoppage due to an unmanaged change. SWEP is a leading supplier of compact brazed plate heat exchangers (BPHE) with six production plants in six countries. The SWEP plant in Slovakia manufactures BPHEs in high volumes using automated, PLC-controlled machines from a variety of vendors including Siemens and Allen-Bradley [Rockwell]. Any unplanned stoppages to these machines must be avoided, as these can result in costly delays to production and disruption to deliveries.

Prior to 2015, SWEP had no formal system in place for managing version control or changes to PLC programs – backups were made manually, with each SWEP site having its own policy for managing this. There were no scheduled backups or version control of PLC programs, either within one site or across multiple sites.

Martin Figura, Team Leader Production IT at SWEP Slovakia s.r.o, who is responsible for managing all production automation across SWEP, realized the problem with this process when a supplier was called in to the Slovakia plant to fix a problem on a critical production machine. As Figura explains: “To resolve the issue, the supplier made some changes to the relevant PLC code and uploaded these changes to the machine, which fixed the problem, but also accidentally uploaded the same changes to an identical machine located elsewhere in the plant. This resulted in an unplanned stoppage to the second machine. We had no PLC backup in place, although, fortunately, I’d made a backup of the PLC program a few days before, which enabled us to get the second machine back online later that day. However, this stoppage resulted in the plant losing half a day of production time, which was simply unacceptable.”

To avoid future costly errors related to version control, this plant installed a Change Management System (CMS): MDT AutoSave. With AutoSave, SWEP can maintain an ancestor history of all PLC and non-PLC files on site. Particularly useful is AutoSave’s schedule compare feature that automatically compares the program in the device with a stored program. This feature detects and identifies changes between the programs so that designated users are immediately notified of changes that may have been unknown or unauthorized.

“Since introducing MDT Software’s AutoSave in January 2015, we’ve had a couple of incidents where the system has really proven its worth. Recently, one of our new operators accidentally deleted some operational parameters on a production machine PLC. I simply downloaded the latest version of the PLC code from AutoSave and within a few minutes had uploaded this to the machine. Prior to AutoSave, this would have taken us at least two hours to rectify,” said Figura. “Another unexpected benefit of introducing the software is that it has become a key part of our business-wide Disaster Recovery Policy. We know that if an unforeseen disaster should occur, we will always have access to the latest version of a PLC program, wherever the machine is located in the world.”

In a world where mistakes and unexpected failures never happen, an Automation CMS would not be necessary. Since that world does not exist, having a CMS is an imperative.

You may also like...