Reduce Downtime with Smart Scheduling
EP Editorial Staff | June 1, 2004
By taking a few extra administrative steps, maintenance managers can implement more preventive maintenance in less time.
For years, maintenance managers have successfully been using enterprise asset management (EAM) or computerized maintenance management system (CMMS) software to decrease unscheduled downtime. But managers whose plants are running at maximum capacity face the classic struggle between maintenance and production. One department needs to idle the equipment for preventive maintenance (PM) to avoid unscheduled downtime while the other must have unbroken uptime to meet its production quota cost.
Maintenance managers can help ease this tug of war by implementing a straightforward approach called Smart Scheduling. Smart Scheduling can reduce planned downtime by as much as 50 percent, making it easier to wedge maintenance into a busy schedule and provide efficiencies that lead to documented cost savings.
Smart Scheduling means coordinating all PM activities for related assets, then using an EAM’s scheduling capabilities to plan ahead and “gang up” maintenance events, ensuring that all necessary resources and materials are available for the time that the equipment is scheduled to be out of service. This will maximize efficiency and minimize downtime. Most EAM software packages can help do this, but some newer programs have features to simplify the process.
For example, in two days a plant is scheduled to complete an annual PM activity on machine A, a key piece of equipment. To complete the PM activity, related equipment must be taken down, including machines B and C for an hour or so, which probably will upset the production manager.
To lessen the blow, the EAM can be used to look a month or two into the future to see if there are any additional PM activities coming up for machines A, B, and C. As it turns out, B and C are due for a monthly PM activity next week, and a semi-annual activity is scheduled for A the following week. Now all four can be done at the same time, minimizing downtime, increasing efficiency, and reducing costs. Or if machine C has a yearly PM activity coming up in two weeks, as long as it is down for the monthly, the yearly can be done at the same time.
Implementing the program
Reaping the benefits of Smart Scheduling can require some extra planning and decision-making. Following are a few highlights of some of the steps involved in implementing a Smart Scheduling program.
Identify common procedures and tasks. Begin the process by fully identifying common procedures, making sure to include all estimated parts, labor, and tools. List labor by craft; determine the PM schedule. Start by reviewing the manufacturer’s recommendations then temper that with experience.
For example, if an uncommon number of breakdowns occur between scheduled maintenance events, plan to schedule events more frequently. Conversely, if following the manufacturer’s recommendations leads to unnecessary maintenance, adjust the frequency based on the experience with the facility’s operating environment.
Write tasks and procedures to cover the required PM. To make sure all the exact resources required to do one particular job are available, duplicate or copy the procedure using those functions in the EAM software. Change items that may not be applicable to the equipment being serviced. With these changes, the procedure is unique to that piece of equipment but the procedure/task list is kept consistent and concise.
If the duplicate and copy links functions are not available in the EAM package, write a generic procedure that can be used repeatedly. Remember to make the tasks applicable to all similar equipment and customize procedures by calling out the appropriate tasks, parts, tools, and craft labor.
Determine a scheduling method. The scheduling function of most software programs gives three choices: “since last completed,” “since last scheduled,” and a metered system based on equipment run time or a calendar.
With the “since last completed” option, if the PM activity is originally scheduled on May 7 but is not completed until May 30, the PM will adjust the schedule to set the next due date on April 30. This can increase efficiency because things are being done only as needed.
Over time, the “since last completed” approach yields an advantage, as it will distribute workloads and schedule tasks based on documented evidence of what you can accomplish in one given period.
The “since last completed” option also has its disadvantages, depending on the EAM software. Older EAM systems usually do not ensure that monthly, quarterly, semi-annual, and annual PM activities come due at the same time. If the monthly activity is done but not the quarterly, it is possible to throw the entire system off track and lose any coordination that may have been established between maintenance activities.
“Since last scheduled” means that the activity is done every 30 days on the seventh of the month, for example. One benefit is that a paper trail is maintained. This method will ensure schedule documentation. But a bigger advantage is that this method will maintain the synchronization between maintenance activities that have varying frequency.
There is also a downside. If a monthly PM activity is scheduled for today but does not get completed until the end of the month, the EAM system will prompt to do it again one week later, which is not necessary.
Metering is the most efficient system. It makes sense to take this approach with PM scheduling. If there is some type of meter on some piece of equipment, that meter can be used to set PM intervals. If the operation is running 24/7, important PM activities may come due in a period of 20 days instead of 30. Conversely, if orders are down and production is running slowly, maintenance events may be able to wait 45 days. This approach is especially useful in scheduling seasonal equipment or any machinery that is operated intermittently.
This method is not limited to hour meters. It can be used with almost anything that can be counted, like the number of boxes that are packed out at the end of the assembly line, the number of parts, or the number of cycles or strokes the machine makes. One meter, at the end of an assembly line, for example, can be used to schedule the maintenance of a whole group of related equipment.
Regardless of the method used, determine the capabilities of the EAM software before making a decision. The scheduling module can be used to look into the future to make sure that everything comes out together.
Schedule different maintenance activities to occur in the same downtime period. To bring PM activities together into the same downtime period, identify when actions are coming due, ensure that schedules are synchronized, and audit procedures to make sure each action is accomplished.
Start by identifying when actions are coming due. Look further into the future—perhaps a calendar quarter, but at least a month. As previously mentioned, if the annual PM is also going to be due within the next couple of weeks, consider scheduling the annual event for the same time the monthly and quarterly events are scheduled.
Communicate the needed downtime to those responsible for operating the equipment so they will not have people idle while the machinery is out of service. Plan ahead and arrange to have all necessary parts, permits, tools, and labor available before the equipment is to be taken out of service.
Make sure schedules stay synchronized, whether using “since last completed,” “since last scheduled,” or a metered system. If they are out of sync, adjust scheduled events to put the entire system back into synchronization.
Finally, audit procedures to make sure they are accomplished as scheduled. Compare estimated labor times to actual times, and update all estimates. Examine actual parts use and correct the procedures to call for the right parts in the correct quantities. Check actual downtime against estimated downtime so that the new data will help to estimate production downtimes in the future. Also, be sure to solicit feedback from the people who actually have their hands on the equipment, then update the PM procedures using what is learned.
Once a system is in place, never stop looking for ways to improve or modify it. Smart Scheduling involves a little more administrative work, but it is well worth the effort. MT