In today’s fiercely competitive economy, most process manufacturers face intense pressures to boost production efficiency and meet increasing customer demands. Now more than ever, consumer and business customers expect a constantly changing breadth of diverse, innovative products, and it can be tough for manufacturers to keep up and be competitive. Inventory managers everywhere have had to adapt to smaller, more targeted runs to meet demand and minimize excess inventory.
Most processing plants are already running multiple products per line per day, including varieties of the same products and, sometimes, totally different ones. This practice has resulted in many more production line changeovers compared to even just a few years ago.
Since new equipment is most likely not an option, manufacturers should investigate how improved changeover procedures can help manufacturing cost per unit. Using electronic work instructions or standard operating procedures (eSOPs) as part of a Manufacturing Execution System (MES) or HMI/SCADA can help recover valuable production time, reduce excess inventory, and control product quality, all of which are critical to a better bottom line.
Reduce the cost of changeovers
Changeover costs are rarely measured but can total thousands of dollars per hour. A one-hour daily changeover on a fairly significant packaging project with the line running 240 days per year could total upward of $1.8 million annually.
The number of changeovers a plant can perform is limited by the amount of time it spends on each changeover. As many labor hours are spent cleaning, adjusting and verifying machine setup, this translates into non-production time and higher costs per unit. If potential issues are not addressed adequately during changeovers such as reducing clean-in-place (CIP) operator errors, the plant can suffer longer startup cycles, more rejected product/batches with costs in the millions, and increased machine malfunctions. It stands to reason that the more often changeovers occur, the higher the likelihood of negative effects.
Key obstacles to rapid changeover include manual processes, which are more time-consuming and prone to increased operator errors and quality risks, in addition to the time required to train operators to constantly perform new changeovers.
The adoption of eSOPs, which walk operators through steps and verify completion, can 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. This will ultimately enable improvements for effective production planning.
For example, a mid-sized manufacturer decided to adjust its production run to half the amount of product, allowing it to change flavors and sizes on the line. However, the move from one line changeover per week to six different line changeovers per week doubled the plant’s equipment failure rate. This slowed down production, increased product rejects and resulted in extremely high operator overtime.
The company found that moving to six changeovers per week brought many new operators into the process, without adequate changeover procedures to guide them. And, the new operators did not have the expertise of the original operators, resulting in more errors and lost time during line changeovers.
By implementing new electronic work instructions about these changeover processes with increased accuracy and speed, combined with its MES, the company saved 25% of its line changeover time and cut its line start issues by 50%. The work instructions captured the knowledge of the company’s most experienced operators and incorporated best practices for faster and better production setup.
Why is this important?
By formalizing line changeovers, manufacturers can leverage the power of information to speed up changeovers and drive increased productivity.
Here are some benefits of eSOPs for process manufacturers:
- Strong adherence to standard operating procedures can be used to ensure that lessons learned actually become part of the way the plant works.
- Improved accuracy and repeatability as eSOPs are much less open to interpretation and abuse, either intentional or unintentional.
- A direct link to the plant ensures safety interlocks remain uncompromised and changeovers are in the sequence that promotes the most effective process.
- Routine collection and collation of masses of data.
- Powerful reporting tools transform data into meaningful information, which is consumable by stakeholders across the organization for better decision-making.
One food manufacturer implemented an eSOP solution with its MES collecting data meant to look at process improvement. Interestingly, a number of course corrections came to light.
The team discovered that some of the same tasks were taking different amounts of time to perform, depending on the operator shift, which pointed to the need for better training. In addition, it discovered that moving through the production mix worked better in one direction than others; for example, reducing the bottle size was faster and easier than increasing the bottle size.
Using this information to gain better insight about its changeovers, the company incorporated new training procedures into its on-boarding of new employees. It also changed its production process order to go from largest bottle size to the smallest bottle size, reducing the overall time of a line changeover by 35%. The significant improvement resulted in less operator overtime, fewer product rejects and reduced equipment failures, driving speed and production efficiency.
Profit from rapid and reliable line changeovers
As some leading companies have begun to discover, the key to speeding up line changeovers without compromising quality relies upon guiding operators through changeover processes. The faster that operators can set up machines and recipes correctly, the more efficiently manufacturers can produce many different products on the same line without changeover delays and errors, recovering valuable production time and delivering consistent product quality.
Of course, you cannot sacrifice quality in the pursuit of speed. The operator is the first line of defense to ensure quality. Many manufacturers have moved toward having the operator perform many of the quality verification steps.
One company realized that changeovers were affecting its product quality and implemented eSOPs to ensure that its operators would not miss any changeover steps. If steps were skipped or performed incorrectly such as CIP, the results were setup errors and costly rejected product. The use of standard procedures prevented operators from inadvertently omitting a step, ensuring compliance with defined processes and minimizing quality issues.
The procedures this manufacturer implemented also enforced the importance of operators to enter critical parameters along the way. This way, process data 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, and the company was able to gain tighter control of the process without additional head count. It also helped to reduce the reject rate.
Rapid and reliable changeovers enabled by electronic work instructions help manufacturers decrease errors and 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.
Joe Gerstl is the director of product management for Manufacturing Software at GE Digital. He has worked in the software industry and in manufacturing for over 30 years, spending time in various roles including engineering, sales and product management. His experience spans from working for startups through leading companies such as Microsoft and now GE. Gerstl has worked with customers in both discrete and process manufacturing segments across all levels of the supply chain.
