Preventive maintenance planning and practices influence most major maintenance department activities in a manufacturing environment. Here are some examples of this.
- Equipment downtime is largely affected by preventive maintenance or the lack there of.
- Repair work orders are subjected to the influences of the preventive maintenance program.
- Purchasing and inventory are affected by preventive maintenance for routine replacement of expendable spares as well as repair parts required for unexpected downtime.
As evidenced by the points above, preventive maintenance should be “first base” for any maintenance department. Unfortunately sometimes routine preventive maintenance activities often do not get the attention or credit they are due. This is a mistake. So what are the keys to a successful preventive maintenance program?1. Careful Planning of the Preventive Maintenance Program
Planning a preventive maintenance program involves the following:
- Determine tasks and intervals needed to maintain the equipment.
- Ensure that the appropriate resources are in place.
- Schedule maintenance personnel for maximum preventive maintenance wrench time.
- Understand how scheduled equipment downtime and maintenance personnel scheduling interface.
- Manage spares effectively.
- Select a scheduling and accountability system (preventive maintenance software, CMMS software or equivalent)
Determine Maintenance Tasks and IntervalsA good preventive maintenance (PM) task list contains the following components:
- The equipment item.
- The task(s).
- The person the task is assigned to.
- A task interval.
- A start date and due date.
- Optional: Detailed instructions and pictures if needed.
- Optional: Task completion sequence.
Begin with your equipment list. Next gather appropriate tasks for preventive maintenance task lists from OEM manuals or online manuals when possible. This is a good place to start, especially with newer equipment. In some cases, the equipment warranty is dependent upon following the OEM recommendations. Another source of tasks is the maintenance manager’s experience and intuition. Yet another source is branch locations running similar equipment.When developing a task list, consider the reusability of the task descriptions. Reusability refers to using the same task description on potentially multiple equipment items. The benefit is that there are fewer tasks, no duplicate task descriptions and better reporting and analysis of PMs. Consider these examples:
REUSABLE task description: Lubricate Roller Chain(s)
NOT REUSABLE: Lubricate Roller Chain(s) on Conveyor #1
In the first example this task, Lubricate Roller Chain(s), is appropriate for any equipment with a roller chain. In the second example, Lubricate Roller Chain on Conveyor #1, is only appropriate on the Conveyor #1 PM task list. Imagine how cumbersome your preventive maintenance software management efforts become if you are not using reusable tasks. Another example that may cause problems later is naming conventions such as 30 Day PMs or Weekly Tasks. This creates unneeded redundancy, as the interval (30 in this case) is included in the PM record already. Additionally there is no task description here that refers to the actual work performed.
How do you create reusable tasks? Begin with the most generic tasks you can think of and create these first. Examples could be Inspect, Clean, Lubricate, etc. After these task descriptions have been created, go to the next step and create tasks that are somewhat more specific. Here are some examples: Check Wiring, Replace Lubricant, Lube Chains. Continue with increasingly more specific tasks always trying to avoid including the equipment or equipment component in the task description. Eventually, for specialized tasks that are only performed on specific equipment, it may become necessary to include a component of the equipment in the task description. Keep the task description short and focused on the actual task. Obviously if the task description is short, it may not fully describe the job. This is where detailed instructions and pictures are used.
Next, determine what interval units are needed for your PM system. Calendar-based PMs usually will use a day interval. For example every 7 days Lubricate Roller Chain(s). Other tasks may be demand based or based upon the actual runtime of the equipment. In some cases, hours or minutes may be appropriate. As you gain experience with this set of PM tasks and intervals changes to the tasks and intervals may be warranted. Consequently choose a system that makes editing existing PMs simple and without historical data loss.
Ensure that Adequate Resources are in Place
Listed below are resources you need for a successful preventive maintenance program:
- Trained and available personnel.
- Adequate spares, expendables, lubricants, drive chain, bearings, etc.
- Time in the production or equipment runtime schedule to perform PMs.
- A motivated team of maintenance professionals.
Personnel must be trained and capable of safely performing the required work. Vigorously enforce proper lockout/tagout procedures. Stock on hand for expendables and other spares used for PMs has to be adequate. Inadequate spares not only prevents completion of the PMs, but also hurts motivation when personnel attempting to perform their job are hindered by a lack of spares. As such, the purchasing department has to have an ordering system that stays ahead of preventive maintenance spares requirements. Additionally an accountability system (CMMS) helps track spares use for restocking purposes. In summary, show your maintenance technicians how important you believe preventive maintenance is by providing the materials and training needed for these important tasks.Time is a resource. Time must be available so that personnel can perform their work. This may require scheduling changes so that maintenance personnel are available during scheduled equipment downtime. Given the right resources, your maintenance team cannot help but be motivated to succeed with equipment maintenance.
Use a Maintenance Software Solution to Track and Manage Maintenance
Now that the tasks, intervals, personnel, training and scheduling are established it is time to load the data into a preventive maintenance software system. With so many CMMS choices, it is important to do your research carefully. Approximately fifty CMMS companies go out of business annually and fifty more replace these. Choose a well-established long-term CMMS company that has a proven record of accomplishment. Ask the following questions when choosing a CMMS:
- How long has the CMMS company been in business?
- How flexible is the preventive maintenance system?
- Are there different task list formats available?
- Is it possible to automate task list issuance?
- Do technicians have the ability to close their own PMs while maintaining the integrity of the data?
- Is it possible to close PMs without leaving the plant floor?
- How easy (or hard) is it to adjust preventive maintenance task schedules?
- Are labor and parts costs easily summarized and reported?
- Is there an objective way to know how to optimize task lists or task intervals based upon downtime or reliability data?
When evaluating a CMMS it is best to run a demonstration copy of the proposed system with your own sample equipment and tasks. Use the system for at least 30 days. Issue preventive maintenance task lists to your personnel. Get their buy-in by demonstrating the usefulness of the system. Prove to yourself and your maintenance technicians that using the software makes both of your jobs easier. Most importantly confirm that this system has the potential to improve equipment availability and reliability.Consider support and training as part of the initial investment. CMMS software training is well worth the investment as it brings the maintenance department up to speed quickly with the CMMS and instills confidence in its use. This leads to better compliance in entering and updating data.
Price is important, however the real cost benefit of CMMS comes not from the initial investment in CMMS but in the ongoing use and benefits derived from that use. Some CMMS software solutions are subscription-based. Others are a one-time investment with a perpetual license. While there are several factors to consider in CMMS selection, initial investment (price) should be a low priority when the budget allows. Ask yourself this question: “Do you want to trust millions of dollars in equipment assets to a cheap CMMS?”
2. Implement Your New Preventive Maintenance Program
Now it is time to start reaping the benefits of your new preventive maintenance program. Here are a few questions to consider when implementing your new PM program:
- Should tasks lists be printed, emailed or simply viewed through a tablet or smart-phone?
- How are tasks closed and what data should be included?
- Who should close the preventive maintenance tasks as they are completed?
- What will you use the system when maintenance personnel are absent?
- Should spare parts lists be included on the task list?
- If spares are included on the task list, should stock levels automatically draw down when the PM is completed?
The answers to these question come down to company policy, industry requirements, regulations and personal preference.3. Assess and Adjust Your Equipment Maintenance Program
Constantly assessing your preventive maintenance program is an integral part of managing this system effectively. Equipment runtime schedules change, equipment demand changes, personnel change, maintenance technologies and procedures change. Your primary assessment tool is equipment maintenance data. The longer you use your CMMS system the more data it accumulates. Assuming that you chose a CMMS that provides extensive analysis and reporting, this data is now a valuable decision-making store. Use this data for OEE (overall equipment effectiveness) and reliability analysis. Choose a CMMS that uses MTBF (mean time between failures) to suggest preventive maintenance task intervals. Using real runtime data to set PM task intervals eliminates guesswork.
Being a proactive maintenance manager you should be adjusting to these changes as needed. Here are some things to look out for and some ideas on how to react. Keep in mind that sometimes there is no substitute for an experienced maintenance manager’s intuition.
Equipment Runtime Schedule Changes
In some situations, preventive maintenance can only be performed while equipment is in a scheduled shut down period. This creates a problem for maintenance scheduling. Here are some ways to manage this situation.
- Non-maintenance machine operators can complete some simple maintenance procedures such as minor lubrication tasks.
- Double-team certain equipment when it is down.
- Adjust maintenance schedules.
- Use automated maintenance devices, such as lubricators.
- Implement preventive maintenance procedures during unscheduled downtime.
Equipment Demand ChangesEquipment demand relates to more than just runtime schedule changes. Demand reflects the actual time equipment is running and how much work it performs during the scheduled period. Obviously triggering PMs based upon calendar days would not be appropriate in these cases. It is best to trigger PMs in this case based upon runtime hours, cycles, cuts or whatever the appropriate meter unit is for that equipment. Consequently this equipment should have a counting device or be connected to the system that automatically triggers preventive maintenance work orders through an OPC compliant data connection.
Select a CMMS software solution that reads OPC data directly from the equipment then automatically responds with a preventive maintenance work order at exactly the right moment.
The best way to overcome this inevitable change is to have detailed listings of preventive maintenance tasks, intervals, spares requirements and history. Make sure this information is available to pass on to the new person. The more organized your system is the easier is to move seamlessly through this change. Once again, a good preventive maintenance software solution addresses this need.
Additionally, ongoing training and cross training in various maintenance processes can offset personnel change issues.
Changes in Maintenance Technologies and Procedures
An example of this type of change could be a new sensor that provides critical maintenance data to an OPC server. This data in turn indicates the correct PM interval. Another example could simply be running the equipment only when needed. This action saves energy resources and may reduce wear and tear on the equipment.
Software is constantly improving. Desired options with preventive maintenance software solutions are as follows:
- Is there a role-based permission capability that allows the maintenance technicians to close their own PMs?
- Is there a mechanism to validate PMs closed by technicians?
- Does the ability to temporarily assign tasks to an alternate maintenance technician exist?
- Is it possible to gather runtime data through an OPC compliant data network and issue work orders automatically.
SummaryPreventive maintenance is the one of the primary responsibilities of the maintenance manager in a manufacturing environment. Many maintenance department activities are affected by, and rely on a successful preventive maintenance program. More importantly, success of the manufacturing facility as a whole is directly proportional to the quality of the design, implementation and management of the preventive maintenance system.