Navigating the Bathtub Effect: A Guide for Managers of Automated Facilities

Introduction:

As manufacturers steer the course of modern manufacturing, the "bathtub effect" concept has profound implications for the maintenance and longevity of automation equipment. This metaphorical bathtub curve represents the failure rate of machinery over time, and understanding how it applies to automation systems is crucial for manufacturers seeking to optimize operations. This post will delve into the bathtub effect and explore strategies for mitigating its impact on automation equipment.

The Bathtub Effect Explained:

The bathtub curve illustrates the typical failure pattern of an automation system. It consists of three phases. The first phase, or "infant mortality," is characterized by a higher failure rate early in the equipment's life. These are typically due to unforeseen initial design issues or small quality issues in components. Next is the stable "normal life" phase with a low and constant failure rate. The system functions properly as parts are broken in, with only consumables and preventive maintenance being the majority of the cost to keep the system running well. The final phase is the "wear-out" phase, where the failure rate increases due to aging components. In this phase, the system gets expensive to maintain as the components reach the end of their effect life span and must be replaced. This high rate of failures results in a large amount of downtime for the facility, further increasing the cost for the facility.

Source: Bathtub curve. (2023, June 21). In Wikipedia. https://en.wikipedia.org/wiki/Bathtub_curve

Addressing "Infant Mortality" with Rigorous Testing and Support:

In the context of automation equipment, the "infant mortality" phase refers to the early stages of operation, where there may be a higher likelihood of defects. Managers can mitigate this risk by implementing rigorous testing protocols during the installation phase. Thorough testing helps identify and rectify potential issues before the equipment is fully operational, minimizing the risk of early failures. Ensuring onsite support from the installers and having spare parts on hand after the initial “Go Live” is also an excellent strategy to work out any issues not caught during testing. While a more extended testing period and stand-by support cost more money upfront, it can allow for a smoother transition into the use of the new system.

Regular Preventive Maintenance to Sustain "Normal Life":

Stable and low failure rates characterize the "normal life" phase. During this phase, regular preventive maintenance becomes paramount. Implementing a proactive maintenance schedule helps identify and address potential issues before they escalate, ensuring automation equipment's continued reliability and efficiency. Having planned preventive maintenance two times a year is standard in the industry and should be planned for when purchasing the equipment.

Implementing Predictive Maintenance for Early Issue Detection:

Predictive maintenance, leveraging sensors and data analytics, is a powerful tool for manufacturers. By continuously monitoring the condition of automation equipment, predictive maintenance enables the early detection of anomalies or wear, allowing for timely intervention and minimizing unexpected failures. Adding tools such as Fanuc’s Zero Down Time (ZDT) software is also a great example of this concept. The software constantly monitors the robot’s conditions and lets you know when a problem may be starting to develop with the robot.

Upgrading and Retrofitting to Extend the "Normal Life" Phase:

As automation technology evolves, manufacturers can explore upgrading or retrofitting existing equipment to extend the "normal life" phase. This strategic approach involves incorporating new technologies or replacing outdated components, keeping automation systems aligned with the latest industry standards and requirements. Some equipment may have a more extended service than others, so it may make sense to replace this equipment before considering replacing the entire system.

Planning for Obsolescence in the "Wear-Out" Phase:

In the "wear-out" phase, aging components may lead to an increased failure rate. Manufacturers can navigate this phase by developing a comprehensive obsolescence management plan. This involves anticipating the end-of-life of critical components, planning for replacements or upgrades, and ensuring a seamless transition to newer technologies. Having software for your system that is open and not proprietary is also important, as being locked into a system can significantly increase cost and reduce options for retrofitting. With extremely large systems that are at the end of their life cycle, it may be a better investment for the company to look at moving to a new facility with a new optimized layout. Business models often change over time, and a new optimized system may be a better option than totally rebuilding a system that has reached its end of life. Especially if you calculate the downtime, with a retrofit, you need to remove an old system and install a new one.

Investing in Training and Skill Development:

The effectiveness of automation equipment maintenance relies on the skills and knowledge of the maintenance team. Manufacturers should invest in ongoing training and skill development to keep the maintenance team abreast of the latest technologies and best practices in automation equipment maintenance. The facility can hire a company for support if it does not have a budget to hire or train its employees in the highly technical skills needed to run an automation system. Many companies now offer 24-hour support for the automation systems they install.

Conclusion:

For manufacturers steering the ship of automation in modern manufacturing, understanding and addressing the bathtub effect is essential. By addressing "infant mortality" through rigorous testing, implementing regular preventive and predictive maintenance, upgrading and retrofitting, planning for obsolescence, and investing in training, manufacturers can navigate the complexities of the bathtub curve, ensuring the longevity and reliability of their automation equipment. This strategic approach minimizes downtime and contributes to sustained operational excellence in the dynamic landscape of manufacturing.