Hidden Bottlenecks: Why Your Production Line Never Reaches Its Theoretical Capacity
Your production line is designed to run at 100 units per minute. The equipment has the required capacity and, when everything is running well, the line reaches its target rate. Yet at the end of the shift, actual production is still below target.
In this situation, the first reaction is often to look for the machine slowing down the line. It makes sense, but that is not always where the problem lies. On an automated production line, lost capacity can come from the way equipment interacts: inconsistent product flow, insufficient accumulation, a product transfer that becomes less reliable at higher speeds, poorly synchronized equipment, or a downstream stop that eventually slows everything upstream.
When our teams analyze this type of issue, they look at what is preventing the line from maintaining its production rate over several hours, under actual operating conditions.
The machine that stops isn’t necessarily the one slowing down the line
A machine’s rated capacity is a good starting point, but it does not explain the performance of an entire production line. A machine capable of processing 120 units per minute may spend part of its time waiting for product from the previous operation. Another may run perfectly until downstream equipment can no longer handle its output. Products begin to accumulate, the machine slows down and eventually stops.
In either situation, replacing or speeding up the machine that stops will not necessarily solve the problem.
On the plant floor, we look for the point where product flow starts becoming inconsistent. Do products repeatedly accumulate in the same location? Is a machine regularly waiting to be fed? Do operators have to step in several times per shift to reposition a product or restart part of the line? Does a very short stop eventually affect three or four pieces of equipment? These observations often help us trace the issue back to the actual bottleneck.
Find what is really limiting the production rate
Some bottlenecks are easy to identify. If one machine has a maximum capacity of 80 units per minute while the rest of the line needs to produce 100, the math is fairly simple. The situations we encounter are often less obvious.
A line may reach its target rate for 15 or 20 minutes before gradually falling behind. The issue may also appear only with a specific format, after a product changeover or when the production rate increases. That is why it is important to observe the line over a representative period and under different production conditions.
Equipment data can help reveal certain patterns, including the frequency and duration of stops, actual production rates, availability and performance losses. That information then needs to be put into context with what is actually happening on the plant floor. When a machine stops, we want to understand the sequence of events that led to it. Was it waiting for product? Was the machine itself in a fault condition? Had the next piece of equipment already stopped? Was the available accumulation full? Did an operator need to intervene?
By tracing that sequence back, we often find a different cause than the one that initially appeared obvious.
Give the line enough room to absorb normal variations
A production line never operates at a perfectly constant rate. There will always be small variations between pieces of equipment. This is one of the reasons accumulation plays such an important role.
A properly sized accumulation zone creates a buffer between two operations. If downstream equipment stops for a few seconds, the preceding machine can continue running while products accumulate. In the same way, having enough product available can allow a machine to continue operating through a short upstream interruption. Without that breathing room, a very short event can quickly spread across several sections of the line.
The solution, however, is not to add more conveyor everywhere there happens to be available floor space. The product being handled, production rates, frequency of stops, changeovers and sanitation requirements all need to be considered. In food processing, product behavior matters. A stable, rigid bottle does not accumulate the same way as a lightweight container, flexible package or product that can be damaged by pressure.
The conveying and accumulation system needs to be designed around those realities.
Going faster isn’t always the solution
This is often one of the more surprising findings when working on line optimization.
A faster machine does not automatically mean more production. If one machine speeds up while the next one cannot handle the additional output, products will simply accumulate faster. On the other hand, increasing the speed of a machine that is already waiting for product will not accomplish much either.
On an automated line, we therefore look at how the different operations are balanced. One machine may need to run faster, but the solution could also involve adjusting speeds, modifying a transfer, adding or changing an accumulation zone, or adjusting the programming that controls how the equipment interacts.
This becomes especially important when equipment from several manufacturers is integrated into the same line. Each machine can meet its specifications and operate properly on its own. The challenge is making sure they work properly together once they are integrated.
That is where looking at the production line as a complete system makes a real difference.
Conveying and controls have more impact than you might think
When a plant wants to increase production capacity, attention naturally turns to the main process equipment: processing, filling, packaging, case packing or palletizing. The equipment connecting these operations generally gets less attention. Yet it can have a significant impact on the production rate.
A poorly designed transfer can affect product stability. An accumulation zone that is too short can cause a downstream stop to travel back through the line. Control logic can create unnecessary acceleration and deceleration.
This is why we pay close attention to conveying, transfers, accumulation zones and controls when integrating a production line. Their job goes beyond simply moving products forward. They need to maintain consistent product flow between machines that do not always operate at exactly the same pace. On a high-speed production line, these differences become noticeable very quickly.
After making a change, go back and look at the line
Once the bottleneck has been identified and a change has been made, there is still one important step: determine what actually improved.
Is the problem equipment stopping less often? Is product flowing more consistently? Are operators intervening less frequently? Are stops still spreading to other equipment? And, ultimately, is the line producing more over the course of a shift? That last result is what matters.
Correcting one constraint can also make another one more visible. That is normal. Once one section is no longer limiting production, the next constraint becomes the new area to address. Line optimization therefore often happens in stages. Identify what is currently limiting production, make the appropriate correction, measure the result and then see how the rest of the line responds.
A high-performing line needs to be stable
A line that reaches 120 units per minute for a few minutes before slowing down or stopping is not necessarily more productive than a line that maintains a slightly lower rate for several hours. For a plant manager or operations director, the ability to maintain that rate over time is what matters. More stable production makes planning easier, reduces interventions and, most importantly, helps bring actual production closer to expected capacity.
When a line is not reaching its targets, the analysis needs to go beyond the machine that appears to be slowing it down. The bottleneck may be in the conveying system, accumulation, transfers, programming or simply the way several pieces of equipment interact. This is where working with a manufacturer and integrator brings a broader perspective.
At Storcan, we work with complete production lines that combine multiple technologies, including processing, conveying, accumulation, inspection, packaging, material handling and end-of-line systems. This complete view allows us to analyze the line as a whole, understand the interactions between different pieces of equipment and identify the constraints that are actually limiting performance. It also gives you a single point of contact to look at the entire issue and coordinate the different areas of expertise required to address it.
At the end of the day, the production rate that matters is not the one printed on a machine’s specification sheet. It’s the rate your line can maintain, hour after hour.
Is your line producing below its expected capacity?
Our experts can analyze your production line, identify the bottlenecks limiting its performance and determine the most relevant optimization opportunities for your operation.