Planned Maintenance: Converting Unplanned Work to Increase Uptime
As a typical rule of thumb in maintenance, planned work will consume roughly one third of the resources (labor cost, materials cost, and costs associated with equipment down-time) as unplanned work will consume. Therefore, the first objective of any maintenance program can be simplified as maximizing the percentage of time and resources spent on planned maintenance, and reducing the amount of unplanned maintenance or repair work resulting from unexpected breakdowns.
Understanding the Types of Work
Planned work can be broken down into two main categories: preventative maintenance and planned repairs. Preventative maintenance includes all the work done not in response to a failure, but to prevent future failures from occurring. This work is typically outlined by the manufacturer in terms of frequency and work that must be performed (oil change, lube, and filter). If the fleet size remains constant, so will the level of preventative maintenance. Planned repairs are work that must be done as a result of wear and tear in which the equipment has not yet failed and can still run reliably until the maintenance department is set up with the required materials, labor, and shop space to adequately address these repairs. For exemplary purposes in this article, we will consider maintenance needed for an underground mine as a model. Due to the travel time in underground mining and the requirement in most cases to have repairs done in the shop after a wash, these two types of planned work are best done together to minimize the mechanic’s trips to and from the equipment.
Given that the level of preventative maintenance will remain considerably flat, as both the materials required and time required can be predicted and cyclical, the only way to effectively increase planned work as a proportion of total work is to increase the level of planned repairs. The first task is to shift the balance of planned maintenance and unplanned maintenance. That is, to convert as much of the resources spent on unplanned work as possible into resources spent on planned work.
Converting Unplanned Work into Planned Maintenance
The first step is to create a backlog, a master list of all known repairs that must be made to each piece of equipment. It consists of repairs necessary to components that are in a partial state of failure, but have not yet failed. The size of a backlog and how well it is managed will provide some valuable insight as to the over-all health of your assets. A complete detailed backlog will also provide other benefits to management when taking a closer look at each type of equipment and analyzing which components require more attention than others. If repairs to equipment must be done before the equipment actually fails, the ability to identify or predict failures before they actually occur will be crucial. Coordination can then be made for the replacement of these components before failure occurs. This can be a very difficult and daunting task when considering a large fleet with complex equipment.
The first element to be considered when creating and managing a backlog is where the backlog work will be sourced from. Where will the maintenance planners get the information to create backlog list? Each time the equipment is inspected, an opportunity is provided to gather backlog. In an underground mining environment, some of these touch points include the preventative maintenance services, planned repairs, and operator circle checks.
An additional inspection can be strategically added to generate a greater and more detailed amount of backlog. Figure 1 below depicts the impact on parts procurement time of an inspection conducted by a mechanic in a predetermined time frame before the equipment is scheduled to come into the shop for a preventative maintenance service.
Figure 1—Current State vs. Future State with Backlog
Once the backlog list has been developed, the repairs can then be strategically scheduled alongside the preventative maintenance services while the equipment is already in the shop with shop space and labor assigned to it. Additionally, once these repairs have been scheduled, parts and materials can be ordered, packaged, and delivered to the shop where the repairs will be completed.
The supply benefits of planning repairs before failure are amplified in underground mining as the remote locations can be difficult for suppliers to deliver to. Even once on site, the materials must go through a complex supply delivery system to make their way underground. Planning these repairs ahead of time allows the equipment to run for the duration of this prolonged lead time. If the equipment is run until failure, it will remain down for the entire duration of this lead time until the needed parts can be delivered.
In generating and completing the backlog list against each piece of equipment, failures and breakdowns that would normally occur can now be discovered before failure and repaired on average much quicker than if the equipment would have broken down. The backlog system is working towards converting unplanned maintenance work into planned maintenance work, and therefore consuming one third of the resources on each repair converted as would normally be expended.
Planned maintenance leads to significant cost savings with improved productivity. For 50 plus years USC Consulting Group has helped organizations develop planned maintenance programs to increase their uptime. Contact us today to start converting your maintenance practices and keep your operations running as much as possible.
