Understanding an Automated System’s Maintenance Needs

Aligning Maintenance with Risk Tolerance

One of the first considerations when planning automated system maintenance is the organization’s tolerance for risk of downtime. The type of application, market, and customer the automated facility serves often dictates the type and frequency of maintenance activities, said Jake Heldenberg, Head of Solution Design at Vanderlande.

“If the automated system is deployed in an operation that is filling e-commerce orders for customers who expect their shipment to arrive within a day or two, unplanned downtime is not an option,” he explained. “The maintenance and support activities need to be much more aggressive and sophisticated to minimize the chance of a system failure.”

“Automated facilities serving retail stores—particularly larger ones selling general merchandise—are frequently comfortable with availability rates around 98% to 98.5%,” he said. “It’s okay if the warehouse gets a couple of shipments out late. Because the stores already have a certain number of days of inventory on hand. Chances are low that the retailer will lose a customer if one item is out of stock.”

Different Maintenance Methodologies

Within the U.S. Department of Energy’s Operations & Maintenance Best Practices guide there are different types of maintenance methodologies. Among them are:

• Reactive Maintenance – This approach avoids all maintenance activities until the automated equipment stops working. The agency estimates that 55% of operations take a reactive maintenance approach. When a system is new, companies may be lulled into a false sense of security because the chances of a failure are low. However, waiting for the system to break prior to servicing it can be costly in terms of unplanned downtime, repair or replacement needs, secondary equipment failures, and increased labor costs due to inactivity and overtime.
  
• Preventive Maintenance – A much more cost-effective method, preventive maintenance activities are performed on a schedule based either on regular time intervals (such as quarterly), or automation run-time targets. This practice is more likely to identify and correct impending component failures before they cause significant downtime. The resulting increase in automation reliability can save an organization between 12% and 18% in costs over reactive maintenance programs.
  
• Predictive Maintenance – These activities are scheduled based on the actual operating conditions of the automation, as determined by collecting and analyzing functional data. With equipment providers increasingly offering Internet of Things (IoT)-enabled functionality, automated systems sport sensors and devices that track maintenance indicators such as temperature, energy consumption, vibration, noise, humidity, and more. Utilizing predictive analytics to inform the timing of service can cut maintenance costs by as much as 30%.

Key Maintenance Service Strategies

To ensure an automated system achieves the desired uptime rate, an operation should employ key maintenance and service strategies. These can be performed by in-house technicians, a team supplied by the automation’s original equipment manufacturer (OEM), or outsourced to a third-party maintenance service provider.

The operation’s maintenance and repair team—if present—should receive initial training on best practices for servicing the automation as part of the installation and deployment. Likewise, it’s wise to stock recommended spare parts such as belts, lubricants, bearings, and other recommended components on site based on their likelihood of failure. The automation’s OEM should provide a list of these spares as part of the deployment.

Optimally, advised Heldenberg, services (or service offerings) at a minimum should include a technical assessment, cleaning, and lubrication of system components and consumable parts. Service should also incorporate planned maintenance activities, including adjusting and replacing worn parts based on a predefined schedule. Condition-based adjustments, replacements, repairs as needed should also be part of a predictive maintenance program, with remote monitoring and technical support available as needed.