When every changeover minute counts

Shandies in multiple flavors, limited-edition seasonal products, different package sizes and country-specific labels: The beverage industry thrives on variety. But the same variety that grabs consumers’ attention on the store shelf increases complexity on the production floor. Because each additional flavor, new label or pack variant needs to be scheduled and filled – and efficiently integrated into existing processes.  

And so, all beverage manufacturers face the same challenge: “These days, if you want to operate cost-effectively, you have to fill efficiently – but it’s just as important to execute changeovers reliably and without errors,” says Martin Sporn of Krones’ product management team for lines and digitalization. Because high line speeds alone are no longer enough for day-to-day production marked by small batches, more frequent product transitions and the downtimes that go along with them. Fast changeovers have become essential to efficient, economical beverage filling. 

A look at the possible consequences of not optimizing changeovers shows why this is important: Every minute that the line is stopped is lost production time, which reduces overall equipment effectiveness (OEE). And every manual intervention increases the risk of error. Therefore, fast changeovers don’t begin with the act of mechanically changing over parts but rather with ensuring that the next order, the correct parameters, the right product and materials and the necessary information about upcoming manual interventions are available at the right time.  

In actual practice, changeovers rarely affect just one machine. Depending on the order in question, machines’ mechanical parts will need to be changed over or adjusted, the new product will need to be selected at the HMI, printers and date coding devices will need to be adjusted, new materials must be made available, cleaning steps initiated and/or routes within the line modified. In addition, coordination needs to happen between operating personnel, shift managers, production planning and the warehouse – but also with the beverage production systems and the higher-level IT systems. 

And it is precisely here that we see why fast changeovers matter for the entire line. When each machine is viewed in isolation, there is a greater chance of operator errors, wait times, double entries or unnecessary manual interventions. On the other hand, when the line is viewed and controlled as a cohesive process, orders and the underlying parameters, materials and any necessary manual adjustments can be perfectly coordinated to achieve a changeover that is efficient from start to finish.

Less manual coordination, more system-based processes

Given these many and varied requirements, it makes sense to use software instead of relying solely on people to do all the associated decision-making and execution. Manufacturers can significantly reduce potential manual errors by using digital solutions to manage and, in some cases, automate the processes involved in SKU changeovers right down to the machine level.  

To coordinate filling and packaging as an integrated process, Krones relies on Line Management as a centralized production control solution that works across all the machines in a line. The software brings together information from production planning, from the machines on the shopfloor and about material flows. It knows which order is up next, which machines will be involved, which route will be used and which products and parameters are required for the respective stock keeping unit (SKU). The result is that the many individual work steps involved become a unified, defined process. The changeover doesn’t begin when the last container for the outgoing batch rolls off the line. Instead, it is already prepared for and coordinated well in advance and executed in a controlled manner. 

One of the primary use cases for Line Management is the centralized, system-controlled coordination of order transitions. Orders and bills of materials can be imported from higher-level systems or entered into the software directly. This is done entirely without paper-based work steps and the human error that often goes along with them. Line Management determines which machines and routes are needed, which product variant or recipe is to be used and which materials must be supplied. This information is then used to automatically set up the correct configuration for the respective order on the machines. 

• Automatic parameterization is a significant advantage. Instead of needing to select programs and settings individually at several different HMIs, operators simply launch the order for the entire line once within Line Management. The relevant information is then transferred from this central point to the machines involved. Printers and date coding devices can also be included so that best-before dates, batch numbers or other packaging information are set to match the order. 
• At the same time, Line Management also supports material flow. It is able to request materials so that they are supplied in time, account for any residual materials and end orders precisely when the tank is empty or the desired number of containers has been processed. A cleaning matrix makes it easier to choose the correct cleaning program or intermediate flushing in between orders. Additionally, operator guidance within Line Management indicates the manual tasks that must be performed during the changeover as well as important events, such as when no subsequent order has been set. 
• Feedback regarding how many units were actually produced in a certain time or which materials were used is provided automatically, directly from the line to the higher-level ERP system and a connected warehouse management system – without the operating personnel needing to input anything manually.  

This deep vertical integration of the software makes for a changeover process that doesn’t depend on individual requests or decision-making but is instead clearly defined and digitally connected to every system involved in the value chain.

Flying batch change: controlled transitions avoid full line stoppages 

The advantage of this centralized coordination becomes especially clear when we look at flying batch changes. Here, the line isn’t emptied completely prior to starting the next order. Instead, consecutive batches are run with a controlled gap between them. While the last containers of the prior order are still being treated in the pasteurizer, for example, the first containers of the new batch are already entering the filler. In order for this concept to work, the starting and stopping points for all relevant machines must be precisely coordinated. Line Management does that, starting and stopping the machines automatically and thus controlling the gap between successive machines and preventing any mixing of the different batches. The advantage is clear: This system saves significant time between filling orders, assuming no lengthy CIP cleaning or manual mechanical changeovers are needed between the orders.  

And that benefit is even more powerful when the production process is accurately tailored to the precise capacity of the tank, meaning that Line Management works with the machines to have the last drop in the tank be the one that fills the last container, thus completely eliminating product waste. The system involves not only the filler but also the upstream machines, for example to prevent too many containers or packs for the current run being fed into the system ahead of an upcoming changeover. In this way, Line Management makes a valuable contribution to resource-saving, sustainable production. Of course, this only works for suitable changeover types. 

Different lines, different options for optimization

The extent to which these processes can be automated depends heavily on the line and the type of changeover involved.  

For non-returnable PET lines, Krones offers LineXpress for a much more comprehensive optimization of changeovers. This solution combines Line Management with UnitXpress modules for fast, largely automated changeovers on all machines. And so, for example, changeover procedures on the stretch blow molder, filler, labeler, inspection system, packer and palletizer can all be supported in a targeted manner – and depending on the specific equipment and changeover type involved, even with fully automatic, operator-free quick-change functionality. This comprehensive, line-wide concept from Krones with the option of guaranteed line changeover times is currently the only one of its kind on the market. 

The UnitXpress modules take over mechanical changeovers that have until now been especially time-consuming – with either fully automatic or operator-supported quick-change functionality depending on the machine type involved. Let’s look at a few examples: 

• On the stretch blow molder, a robotic arm takes care of changing of the molds, independently retrieving them from or putting them into staged magazines. 
• At the filler, too, key changeover tasks can now be performed without any operator intervention: Handling parts and the discharge area of the filler as well as the entire capper are automatically adjusted to match the new container height and diameter. Additional software modules support product changeovers between the Contiflow mixer and the Modulfill filler, thus minimizing product waste and shortening transition times. 
• On the packer, the spectrum ranges from fully automatic rail-width adjustments on conveyors at the infeed and discharge to partially automated adjustments with a digital display and audio and visual assistance.  

All in all, UnitXpress offers a modular toolbox that can – depending on the line and equipment involved – shorten format (handling-parts) changeovers to around 30 minutes and product changeovers with an intermediate flush to 10 to 15 minutes – all with enhanced reproducibility. In PET lines, that can translate to an OEE increase of up to 20 percent. 

The situation is even more complex when it comes to returnable-bottle lines for glass and PET. That’s because there is an added factor here, beyond the product, recipe and packaging. Machine parameters must be loaded, routes selected and automatic emptying, start-up and stopping of the machines initiated, just like on the other line types. Additionally, though, the filling line must be supplied with the correct empty containers and crates at all times (at line start-up, during ongoing production and at the end of production) in order to prevent back-ups and material bottlenecks. So the line personnel must manage the balance of crates between the unpacker and the packer and ensure that empty crates are transferred to the packer just in time. Likewise, the sorting stations must be monitored and, in response to variations in the quality of the empties, additional bulk glass must be fed in from storage at just the right time. This extremely high level of complexity combined with the lengthy time from unpacking to packing means that it is hardly possible anymore for operators to keep track of all areas of the line and control each machine individually.  

This is precisely where the value of a solution like Line Management becomes apparent, as it centrally manages orders, material flows and machine parameters across the entire line. Although it isn’t possible to fully automate every last step as it is with LineXpress PET, individual UnitXpress quick-change options are available for selected machines. 

For canning lines, on the other hand, the emphasis is more heavily on intelligent line coordination. The distance between the can infeed station and the filler is usually large, which frequently causes coordination problems between the machines involved. Often, empty cans continue to be fed into the line right up to the end of the current fill run, which of course means that the conveyor is full of cans all the way to the filler – and these extra cans must be removed and disposed of by hand. That costs time and money and is also bad for the environment. When the can height, diameter and lid remain the same from one run to another – meaning that only the product or can design changes – Line Management can make the transition considerably faster and more structured, stopping the sweep-off depalletizer when enough cans have been fed into the line to fill the product remaining in the tank. That makes the canning line more flexible, particularly for co-packers and manufacturers with numerous SKUs – even without having every individual mechanical process automated. True format changeovers, on the other hand, may still require mechanical interventions, for instance on the seamer. Optional UnitXpress quick-change functionality is also available for certain machines in a canning line. 

The sheer variety of options shows that there is no one-size-fits-all solution. Instead, Krones takes a scalable approach: We focus on those places where a given changeover process offers the greatest potential efficiency gain – whether software, mechanical or a combination of both.  

Faster changeovers are only part of the benefit. What is equally important is that the processes are rendered more reliable and easier to manage. When orders, machine parameters, materials and cleaning steps are centrally coordinated, the dependence on manual coordination and on the knowledge and experience of individual workers is reduced. 

It enables production managers to plan more reliably. In real conditions, changeover times become more repeatable and on average measurably faster than they would be without digital support. Material needs become more transparent and targets become more precisely achievable. The risk of common errors (such as selecting the wrong variant, incorrect best-before date, forgetting materials or running the wrong cleaning process between two SKUs) is reduced. 

And so, variety in the production portfolio is not automatically an efficiency problem. Manufacturers can better integrate smaller batches, more frequent order changes and short-notice demand from the market into their production planning. Line Management and LineXpress (or UnitXpress quick-change functionality) lay the technical foundation by turning SKU transitions, which have up until now been a manually coordinated process, into a plannable, digitally supported and automated line process – whether only on the line itself or all the way through to the ERP system, the warehouse or quality management systems. Faster, more digital and more transparent than a traditional changeover.