Package printers know all too well how important it is to minimize changeover time.
Whether the machine is a rotogravure or flexographic press, sheet-fed or web-fed, moving production from one job to another is a big undertaking. Cylinders need to be swapped out, and inks must be changed, critical parts cleaned. Machine builders make bold claims about the speedy changeover features they embed into their equipment design. But once on the floor, how can the printer know how much time do these changeovers take?
A major US-based manufacturer of package printing uses ei3 Downtime Tracking to hone in their operations by carefully tracking and studying downtime reasons to optimize operations.
ei3 has a vast library of proven data collection solutions to monitor industrial printing machines – web-fed and sheet-fed. The running and production status of these machines is recorded in the ei3 cloud by monitoring data values from within the existing press control systems. Every major press manufacturer has a PLC controller or computer management system with readily accessible stop codes that are ready for integration into the cloud. These stop codes have different names, Error Codes, Stop Reasons, and others, but in the end, they are digital signals that indicate why the press stopped. ei3’s Downtime Tracking analyzes these industrial press downtime reasons and maps those individual machine codes into customer-defined downtime reasons in the time tracking database.
Map the downtime reasons into a standard structure
The downtime reason mapping is essential because it gets the diverse values from all printing machines into a system of “apples to apples” comparison. For example, on a web press, one thing that disrupts production is a web break – that’s where the printed sheet tears in the machine – requiring the machine to be re-thread or worse, ink cleaned up. Everyone in this industry knows what a web break is, but it is called different names by different press manufacturers. Even more confusing is that the web break will have different codes in the press PLC controllers. In ei3 these web break events all map to the same downtime reason that the machine owner calls “web break”. This allows for a report to be run to see the MTBF and MTTR by press maker, showing which machines are easier to restart. The same report organized by job may show which substrates break more often helping drive purchasing decisions.
Allow operators to add their knowledge
Machine operators add tremendous value to Downtime Tracking by adding their own codes and comments. With their eyes on the machine, operators observe and comment on downtimes that originate from the machine controllers. More importantly – many downtimes are the result of someone pushing the stop button. The operators use ei3 apps to enter their reasons for pushing stop – for example, job changeover, company meeting, lunch break. With this information comparisons are made using ei3 reports. The changeover times are evaluated by press OEM, by shift, by the customer and other significant differences. These downtime reports are used to drive continuous improvements.
After using the solution for six months on a plant floor, the manufacturer was able to measure a 5% reduction of machine downtime in total.
This reduction was driven in part by the creation of an uptime focused culture. Reporting on accurate measurements motivated everyone to change their work. For example, operators began to pre-stage their job changeovers by positioning the right printing cylinders in advance. They also began to look harder for ways to avoid web breaks by letting purchasing know which suppliers provided better films – which was associated with a press-time based ROI. After the first six months, the amount of downtime continued to reduce. This ongoing reduction was driven by the continuous improvement teams who use the ei3’s Downtime Tracking Pareto features as a part of their plan, do, check, act process.