Unplanned stops in production is an obvious area of improvement. Unplanned stops are driving up downtime, they increase reaction time of the maintenance crews, and disturb the workflow of production and maintenance crews.
Pareto charts help to identify the production disturbances. This chart type is very helpful to focus the attention on repeating issues.
Our data shows that typically 70% - 80% of all production issues are repeaters.
Repeaters:
- Biggest impact after elimination
- Potentially systematic
- Indicates that we have not learned from the past
- Annoying for the individual worker who “keep” experience them
Root cause analysis is a tool to understand the systematic behind a repeating issues.
Standard strategies for typical production issues
For some production issues there are standard strategies that can be applied before a deeper root cause analysis can be performed.
Standard strategies help to act now as a full root cause analysis can take time to complete.
These standard strategies often focus on avoiding unplanned stops by moving equipment maintenance work to planned maintenance windows. Some actions can be considered preventive maintenance.
Cleaning & lubrication (unplanned)
Cleaning and lubrication are part of equipment use. Those activities should not be needed during production.
How to identify
- Look in your logs for “sensor cleaning”, “oil [component]”, “grease [xxx], etc.
- Check the log if this happens repeatedly
- Check if the cleaning is not triggered following an accident/crash/other stop reason but it triggered on its own.
What to do
- Check if the cleaning / lubrication is currently on the maintenance schedule already and adjust the planned interval if it’s already scheduled.
- Schedule planned cleaning or lubrication during planned stop windows. Can be based on time interval (every X weeks) or can also be performed during changeover
The history chart in Peoplegeist helps you identify a suitable interval.
Scheduling planned cleanings is a preventive maintenance action. It the symptom is new it is worth to investigate why this started to be an issue. Why you need more regular cleaning.
- Supplies changed
- New SKUs
- It’s not done properly
- …
Consumables & emptying
“Replace filter”, “refill oil”, “top up coolant”, “drain reservoir”, “drain sump”, …
Many machines require consumables by design. Running out of those during production is an avoidable problem.
Watch out not only for refilling but also for “overfilling” collection tanks for consumables.
How to identify
- Search for topics above “replace”, “refill”, “empty”, “drain”, “overfilling”
- Is it by design? If not there might be a component fault
- Are the consumption levels in line with manufacturer specs? If not you might have a leak or other irregularity.
What to do
- Schedule respective actions as part of regular maintenance.
- You can also do regular inspections if topping up is needed. E.g. During changeover you check if the oil levels are ok and the collection tanks are under a threshold.
You can find regularity by checking the history of the event with the history chart in Peoplegeist.
Wear and tear of components
Having mechanical or chemical wear after usage is normal and to a certain degree “by design”. The manufacturer should provide guidance what components “wear down” and what their expected lifetime.
How to identify
- Regular replacements of components that are exposed to mechanical or chemical stress.
- The replacement of the part is repeating
What to do
- You have an indication that it’s going to fail soon (visual wear, brittle, reduced performance / draws more energy, makes noise):
- Schedule inspections and check for these early indicators. Schedule replacement in regular maintenance window
- Schedule inspections and check for these early indicators. Schedule replacement in regular maintenance window
- No simple early indication available:
- Consider having spare parts on stock. If it breaks, you can switch quickly.
- Switch preemptively based on schedule or usage if the stoppage costs are high enough to warrant the replacement costs.
- Electrical components:
- Typically, failure of electrical components is hard to predict.
- There are influences that allow for inspection and preventive actions:
- Signs of overheating / prolonged high temperature
- Signs of corrosion / leaks from parts
- Check state of fuses
- Check power voltage within spec
- Wear on cables/cords due to vibration/movements
- Check connections exposed to vibration/movements
- Check battery performance / holding charge etc.
Calibration & alignment of measurement tools and equipment
Sensors and measurement tools often need regular calibration in order to ensure accurate readings. Calibration can happen as part of a line-change but also time based.
Re-alignment of tools may also be necessary for automation tools (robot-arms, CNC-axis, conveyor systems, …). For example after certain usage a robot arm may need to be reset to the 0-point.
Mis-calibrated or mis-aligned equipment can lead to wrongful rejection of products, production out of tolerance, line-stops due to automation problems.
In some industries calibration is also important to stay compliant with certain quality standards.
How to identify
- Tool or equipment needs alignment to continue working outside of planned schedule.
- Action is not part of regular line-change or line-restart after an unrelated crash.
What to do
- Schedule calibration as part of regular maintenance.
- Inspect alignment of equipment as part of regular maintenance.
- Consider training operation to do such tasks.
You can find regularity by checking the history of the event with the history chart in Peoplegeist.