Bottlenecks in Manufacturing: Types, Causes, and How to Solve Them

What are bottlenecks in manufacturing?

Bottlenecks refer to operations that constrain a site’s ability to meet production demand within a planned schedule. They are often extremely difficult to identify and even harder to understand. It’s easy to speculate about what is causing congestion in your production process, but unfortunately, bottlenecks often resemble a revolving door – the most critical issues can change by the moment. While merely locating a constraint can bring about important insights regarding an organization’s production process, conducting thorough bottleneck analysis has far-reaching implications, leading to higher efficiency, lower costs, and reduced waste.

What causes bottlenecks in manufacturing?

• Outdated equipment

One of the most common causes of a bottleneck is outdated equipment. If a machine is not performing to specification, it might be the source of your most critical bottleneck. If your employees are trained, procedures run smoothly, and other equipment is performing properly, an outdated machine might be the source of your delays. Outdated equipment is typically considered a long-term bottleneck when the affected machine is not efficient enough to keep up with the capacity of the rest of the production line. This can be solved by repairing or replacing the equipment that’s not up to date.

• Breakdowns

Outdated or overused equipment can also lead to breakdowns, potentially resulting in significant delays for maintenance or replacement. Equipment breakdowns are usually considered short-term bottlenecks assuming the necessary repairs can be performed in a timely and efficient manner.

• Bad forecasting

Poor forecasting – predicting too much or too little customer demand – is another frequent cause of bottlenecks. Overestimating demand can lead to excess inventory, while underpredicting can cause bottlenecks due to supply chain issues. Further, bottlenecks caused by inaccurate predictions can cause missed orders and ultimately customer dissatisfaction.

• Absent workers

Short-term bottlenecks are often caused by absent workers when there is no backup due to a missing skillset. Whether an employee takes a planned leave for vacation or calls in sick at the last minute, the absence of their skillset can slow production if there is no backfill.

• Communication

Effective communication ensures an efficient and clear process in any setting. Communication breakdowns, on the other hand, can grind production to a halt. This can be caused by the failure to provide adequate updates or feedback to workers, causing confusion or distrust.

There are some obvious techniques to mitigate some of these challenges. You can cross-train and plan for employee leave for absent worker bottlenecks and can avoid communication bottlenecks by fostering an open and engaging environment. Even with significant preparations, however, the practice of manually recording data is often time-consuming and prone to error. Mistakes and inefficiencies can lead to prolonged downtime that can impact production schedules and throughput. AR work instructions can ensure speed and accuracy when it comes to machine maintenance and other routine procedures on the manufacturing floor.

Types of bottlenecks

• Short-term bottlenecks

Short-term bottlenecks, usually caused by absent workers, are temporary. As these constraints are transient and easy to pinpoint, they are not usually a significant problem. While it’s difficult to account for all short-term bottlenecks faced by an organization, it is possible to be prepared for most. Prioritizing proactivity ahead of employee absences can help get ahead of the bottleneck.

• Long-term bottlenecks

Long-term bottlenecks can take a significant toll on productivity. Whether they are caused by inefficient equipment or disorganized processes, these types of constraints are most concerning for manufacturers because they are often harder to locate and understand.

• Bottlenecks in static systems

Sometimes, bottlenecks occur without random or unexpected fluctuations in the system. Static environments experience bottlenecks that do not change in behavior and occur without changeovers or systemic breakdowns. In a static system, the step of the process with the longest cycle time will always be the bottleneck. Static systems only exist in theory, since all real-world manufacturing processes are subject to random environmental changes.

• Bottlenecks in dynamic systems

When a system is subject to random changes and outside factors, it is dynamic. These types of systems are broken down into two categories: stable dynamic and unstable dynamic systems.

• Stable dynamic systems are affected by random events, however, these events are consistent over time. All manufacturing processes experience some change, though, even if it is just the replacement of an outdated machine or an uptick in absent workers around the holidays.

• Unstable dynamic systems are more common. All processes are considered unstable dynamic systems when examined at a high level.

How to identify bottlenecks in manufacturing

In order to find root causes and drive insights to gain a competitive advantage, you need to identify your top performance issues. Pinpointing and understanding critical bottlenecks is the first step toward driving throughput and boosting OEE.

• Look for accumulation

The first step in bottleneck identification is locating the production line process that accumulates the most. This method is especially effective when applied to manufacturing lines that process single items – that way, you can easily locate the source of the accumulation and apply solutions to the exact bottleneck location. If accumulation occurs at multiple places on the production line, you might have to dig deeper by analyzing factors such as throughput rates and resource utilization. By thoroughly understanding the dynamics of the factors at play, you can pinpoint the key bottleneck and prioritize your improvement efforts for maximum impact.

• Adjust throughput

Throughput, the amount of a product a company can produce within a specific timeframe, is directly linked to the manufacturing floor’s bottlenecks. An uptick in output on a machine that is not a constraint will not have a large impact on overall production, because the bottleneck is the main limiting factor. By changing the throughput on machines one at a time, you will eventually locate the bottleneck by identifying the machine with the largest impact on overall output.

• Map your process

Value stream mapping, often used in lean manufacturing, is the practice of making a visual guide of all the information and materials necessary to complete the manufacturing process. It can help teams further optimize their process by visualizing where bottlenecks take place. Value stream mapping helps eliminate bottlenecks and waste and paves the way for continuous improvement by focusing on future advancements.

How are bottlenecks removed in manufacturing?

The People, Process, Technology (PPT) framework is a holistic approach that illustrates the interdependence between employees at any given organization, the technology available to them, and the processes they follow. By examining these three fundamental elements, organizations can begin to understand what is needed to eliminate bottlenecks and bring about impactful change.

• People

People will need new skills and training to perform their jobs better and experience a behavioral shift. By hiring and training the best people, you can ensure that your workers will have the skills to leverage the best technology to tackle the task at hand. It’s important to remember that acquiring the right people is important, however, so is ensuring they have a clear definition of their responsibilities. Communication – especially when it comes to expectations and training – is key to making sure employees have a thorough understanding of your organization’s manufacturing process and the bottleneck at hand.

• Process

The actions you take to remove bottlenecks should be streamlined, simplified, and optimized. Your process is tightly related to how you communicate with workers, as it should be clearly defined to achieve your desired outcome: getting rid of the most critical bottlenecks.

• Technology

In this case, the goal of technology is to give employees the tools they need to remove the bottlenecks. Technology should not lead the transformation, since it requires the support of people and processes to move forward. Transformation should guide technology adoption and implementation, which requires the clear communication of objectives to trained and equipped employees to be successful.

PTC’s Bottleneck Analysis capabilities help workers sift through all the data collected on the manufacturing floor by transforming high-level data into real-time insights. Bottleneck analysis allows manufacturers to:

• Understand hidden issues and bottlenecks by quickly identifying high-impact constraints

• Identify root causes of constraints by utilizing advanced analytics to provide visibility and insights

Conclusion

Bottlenecks come in different shapes and sizes, and it can be easy to mistake one for your most critical issue when a larger constraint is looming in the background. Maybe your organization exhibits the traits of an unstable dynamic environment but you can’t pinpoint what events are causing congestion, or perhaps you are actively trying to combat poor forecasting and fragmented communication on the manufacturing floor. Bottleneck analysis can act as an agent for efficiency and productivity by allowing you to gain insights into the weakest links in your production process in real time.

PTC’s ThingWorx Digital Performance Management (DPM) allows for full transparency on the manufacturing floor, giving you the power to understand your vulnerabilities and act proactively. With DPM, organizations can compare and set priorities based on the single metric of time, meaning they can recapture their lost production hours and increase effective time by over 20%.