In today’s competitive economy and varying supply chain, manufacturers face pressures to increase production efficiency and meet increasing consumer demands, while still keeping their focus on quality. Consumers expect a breadth of diverse, innovative products, and manufacturers have to adapt to smaller, more targeted production runs to meet demand and minimize excess inventory. Add to that post COVID regulation changes and stringent food safety practices, the war in Ukraine, and challenging workforce dynamics including worker shortages and a retiring workforce.
Most manufacturing plants run multiple products per line per day, including varieties of the same products as well as different ones. Different products produced on the same line have resulted in more production line changeovers in the factory compared to even just a few years ago, which often required processes, people and equipment to adapt accordingly. And changeover strategies that are successful on a product line need to scale to an enterprise level through best practice sharing and leveraging cloud and analytics.
With capitalization of new equipment out of the question for many companies, manufacturers need to look at improved changeover procedures to ensure that quality is maintained in the process. A critical enabler is speed because the number of changeovers a plant can perform is limited by the amount of time it spends on each changeover.
Most plants spend a significant amount of time on changeovers between runs, which translates into non-production time and higher costs per unit. Key obstacles include manual processes, which are more time consuming and prone to increased quality risk, and the time required to train operators to constantly perform new changeovers.
To address this issue and associated risk, companies have successfully enabled rapid changeovers through the use of electronic work instructions, also referred to as electronic standard operating procedures (eSOPs), to effectively guide operators through the process. Electronic work instructions in manufacturing software help companies gain the agility and speed needed to efficiently produce many different products on the same line without changeover delays, enabling the recovery of valuable manufacturing time, consistent product quality, less waste, and reduced excess inventory, all of which are critical to a better bottom line.
Manufacturing software, particularly manufacturing execution systems (MES), can drive electronic work instructions with automatic data collection and integration with level-2 equipment to download product specifications and operating parameters. These eSOPs are easy to learn and follow—not requiring an experienced hand.
It is important that eSOPs facilitate mobility. Workers today are no longer tied to a terminal on the plant floor, and they are demanding information in the same format and form factor as their daily news on their phone or tablet.
Bottom line issue
Changeover costs are seldom measured but can total as much as tens of thousands of dollars per hour. Most companies build this cost into the base investment because it was not performed frequently enough to track during their large production runs. It is estimated that for a one-hour daily changeover on a fairly significant packaging project with the line running 240 days per year, the annual cost is $1.8 million.
Line changeovers equate to non-production time with many labor hours spent cleaning, adjusting, and verifying machine setup. They also introduce greater risks because issues not addressed properly during changeovers can cause longer startup cycles, more rejected product, and increased machine malfunctions. It stands to reason that the more often changeovers occur, the higher the likelihood of negative effects.
For example, one manufacturer adjusted its production run to half the amount of product, allowing it to change flavors and sizes on the line to gain a more flexible production inventory level. But when it changed from a one-line changeover per week to six line changeovers per week, the plant’s equipment failure rate doubled, which slowed down production, increased product rejects, and also resulted in extremely high operator overtime.
The company decided to take a step back and examine what happened: at the top of the list were ineffective changeovers. As it moved from one changeover to six changeovers per week, many new operators were brought into the process, but there was a lack of changeover procedures to guide them. Additionally, the new operators did not have the tribal knowledge or expertise of the original operators, opening the lines to more errors and lost time during line changeovers.
To address this challenge, the manufacturer implemented new electronic work instructions for changeovers to guide each worker through the tasks required to get the line ready for the next product or size change. These workflows captured the tribal knowledge of the company’s most experienced operators to help make every worker “the best worker” and incorporated best practices into the work processes for faster and better production setup. As a result, the company reduced its line changeover time by 25% and line start issues by 50% for significant time and cost savings.
In today’s environment where there are constant changeovers, manufacturers can leverage the power of information to speed up the process of changeovers, driving increased productivity and maintaining quality for a better bottom line. The use of eSOPs help systematize best practices and provide valuable information and critical visibility into changeover processes, including how long each step actually takes and where and why issues occur— enabling improvements for effective production planning.
For example, one food manufacturer implemented an eSOP solution and turned its process improvement team onto the data. The team discovered that the same tasks were taking different amounts of time to perform, depending on the operator shift, which pointed to the need for better training. Additionally, it discovered that moving through the production mix worked better in one direction than others; for example, reducing bottle size was faster and easier than increasing bottle size.
The valuable insight gained from the use of electronic work instructions enabled a food producer to uncover a significant improvement opportunity that led to the reduction of the overall time for line changeovers by 35%. The significant improvement resulted in less operator overtime, fewer product rejects, and reduced equipment failures—driving speed and production efficiency.
A Game of trust
One manufacturer’s vice president of quality said that quality is “a game of trust but verify.”
Generations of companies have taken on different mantras to ensure quality, including “do it right,” “continuously improve,” and “Lean/Six Sigma.” Many of these companies know that the operator is the first line of defense and have moved toward having that critical employee perform many of the quality verification steps.
One company realized that changeovers were impacting its product quality and implemented eSOPs to ensure that its operators would not miss any changeover steps. If omitted these missed steps could result in setup errors and rejected product. The use of electronic operating procedures prevented its operators from inadvertently skipping a step, confirming production compliance with defined processes, and minimizing errors that can lead to quality issues. The workflows also forced operators to enter critical parameters which could be verified against quality standards automatically helping to ensure that the line was set up correctly and ready to run. With valuable information on product quality, operators could quickly respond to issues, allowing them to gain tighter control and reducing rejects.
The significant advantages of eSOPs include:
- Strong adherence to standard operating procedures can be used to ensure that lessons learned actually stick.
- Improved accuracy and repeatability are much less open to interpretation and abuse, either intentional or unintentional.
- A direct link to the plant to ensure that safety interlocks remain uncompromised and changeovers are followed in exact sequence.
- The ability to automate what people are poor at doing: routinely collecting and collating masses of data.
- Powerful reporting tools that transform data into meaningful information, which is consumable by stakeholders across the organization for better decision making.
Rapid and reliable changeovers enabled by electronic work instructions help manufacturers leverage improved predictability to drive proactive planning of resources, including the reduction of excess inventory. The critical insight manufacturers gain into real-time production helps drive increased agility across the plant—accelerating profit margins for a stronger bottom line.
As some leading companies have begun to discover, the key to quickening line changeovers without compromising quality relies upon guiding operators through changeover processes with electronic work instructions. The faster operators can set up machines and recipes correctly, the more efficiently manufacturers can produce different products on the same line without changeover delays and errors, recovering valuable production time and delivering consistent product quality.