Finding the right measure: Tips on measuring packaging efficiency
How can you reach maximum efficiency with your cartoner, tray packer, case packer or palletizer? To achieve improvements in packaging line efficiency you need to understand your current line performance and necessary adjustments. These 3 steps will put you on the right track. Follow them and find the improvements that can save valuable time and money and increase efficiency across your entire line.
Step 1. Determine Your Maximum Production Rate
Note and verify production operational rate for each machine’s. Make sure that each one is at least a little faster than the preceding unit. Than multiply the slowest machine’s speed by the operational time and calculate the maximum production rate. This can help you identify where improvements need to be made.
Step 2. Identify and Define Causes of Line Stops
Accurately identify the causes of line stops. Note any variables that are affecting a machine’s efficiency. When analyzing line stops look after and evaluate these things:
- Operational time
- Ambient conditions, including air and electricity
- Power supplies
- Packaging supplies
- Contaminant buildup
Be consistent if you aim towards creating operational efficiency —no temporary solutions or promises to look at things later. Identify the settings and the materials that produce optimal efficiency and do everything that you can to maintain them. Make sure that all issues found are fixed permanently.
Step 3. Establish Center Line Operating Parameters
Establish center line operating parameters for each machine along your line. Once you establish operational center lines for flexible production lines lock them down. If it is not possible at least limit the possibility of adjustments being made outside of the center lines.
This entire process can sometimes be time-consuming, taking days to monitor each adjustment and the result. Once they are found and noted, it is much easier to troubleshoot the variable causing lower efficiency later on.
Sometimes is appears that there is a million ways evaluate the performance of your cartoners, case packers, tray packers and other packaging machinery. People measure the efficiency of the line, its throughput, if the equipment is operating at maximum speed, and so on. This information can give you a measure of a piece of the equipment but not an overall view of effectiveness. This is why we recommend using Overall Equipment Effectiveness (OEE) calculations. These calculations provide a big picture view of your packaging machinery performance. According to PMMI’s 2017 Trends in Food Processing Operations Report, 3 out of 4 companies measure OEE. This is not a coincidence: this calculation provides objective, powerful, data-driven insights into areas of opportunity to maximize equipment effectiveness.
Factors Affecting OEE
PMMI’s Primary Packaging Line Playbook describes Overall Equipment Effectiveness as a combination of three factors:
- Availability – Make the things at the right time (keep the machine up and running, minimize downtime)
- Performance – Make the right thing (the right SKU at the right speed)
- Quality – Make things the right way (no defects, rework, or waste)
As you can see, OEE is a measure of where you can improve in your packaging process.
OEE Terms Defined
Equipment availability refers to the percentage of scheduled time the machine is available for operation. Availability takes into account factors that cause a machine to stop when it is supposed to be running. Planned maintenance that takes place during working hours should be subtracted from availability. On the other hand, if planned maintenance occurs during a planned shutdown, it will not affect OEE.
Factors affecting availability can include:
- Operators’ break times
- Performing changeovers to package different products or SKUs
- Planned or unplanned maintenance
- Equipment failure/breakdowns
- Machine set-up and adjustment
For example: a standard shift is 8 hours, or 480 minutes. Let’s assume that operators take a 30 minute lunch and two 15 minute breaks. Also let’s imagine that they performed a changeover that requires 30 minutes to complete. So, of the entire 480 minute shift, the machine is running 390 minutes, or is available 82% of scheduled time.
Availability = 390 min actual runtime/ 480 min scheduled runtime = 82%
Every piece of packaging machinery has an ideal cycle time (the time it takes to complete one bagmaking/filling/sealing cycle). Performance is measured against that ideal cycle time. In the OEE calculation performance represents the speed at which the machine is currently running as a percentage of its ideal speed.
Minor stoppage, idle time and reduced operation speeds will negatively affect performance.
Now, let’s go back to the packaging equipment in the previous example. Assume that it ideally completes 60 cycles per minute (cpm), or one bag per second. But that machine cycle time has slowed and is currently operating at 50 cpm, or one bag every 1.2 seconds. So the equipment is currently running at 83% of ideal performance.
Performance = 50 actual cpm / 60 ideal cpm = 83%
How many packages created were according to specification? The ideal answer would be ‘all of them’. Unfortunately there may be a loss of some product due to improper/inaccurate fills, faulty or leaky seals or issues with package contaminants. Rework, scrap, defects and reduced yield are factors that negatively affect quality.
Quality is represented as the portion of saleable units as a percentage of total units produced.
If 5050 units of 19,500 produced were out of specification and did not pass quality checks then only 14,450 were actually saleable. Therefore, quality is at 74%.
Quality = 14,450 saleable units / 19,500 total units produced = 74%
Overall Equipment Effectiveness
OEE is computed by multiplying availability percent by performance percent by quality percent:
Availability (82%) x Performance (83%) x Quality (74%) = 50% OEE
So what exactly does this measure mean? The equipment is 50% effective, so it looks like there is room for improvement in all areas. This is the case where a complete process audit should be conducted. This audit should focus on steps of the process that affect packaging machine availability, performance, and package quality.
When performing an audit in order to improve Overall Equipment Effectiveness we recommend addressing the following questions:
- Are employees’ breaks staggered to allow for constant running of the machine?
- Do packaging machine operators need additional training to better recognize and proactively address minor problems?
- Do you have critical spare parts on hand at all times?
- Do your packaging machines feature quick, tool-free changeover?
- Is there opportunity for additional automation in the system?
- Can your packaging machinery accommodate multiple bag sizes and styles?
- Are the machine’s jaws producing improper seals?
- Is a preventive maintenance program in place and are periodic service audits performed?
If your goal is maximum efficiency, make no compromises. Only the latest, the most reliable machinery combined with good management can give you the results you want. Check out our cartoners, case packers, tray packers and palletizers and make your first step toward maximum efficiency.