What Is Reliability, Availability and Maintainability (RAM)?

The reliability, availability and maintainability (RAM) concept is a critical maintenance management framework used to ensure assets perform effectively, to minimize equipment downtime and to optimize maintenance strategies.

Imagine you’re running a small fleet of delivery trucks. One day, a truck breaks down unexpectedly, delaying multiple deliveries. The unexpected delay in delivery and potential loss of business can be frustrating, but here’s how RAM could’ve helped:

• Reliability: Turns out the truck broke down because the fuel pump failed earlier than expected. If the truck had been more reliable, the failure wouldn’t have occurred prematurely.
• Availability: The breakdown meant the truck was unavailable for the day. You had to scramble to reroute deliveries to other vehicles. If the truck had better availability, this wouldn’t have happened.
• Maintainability: The repair took much longer than necessary because the fuel pump wasn’t readily available. Better maintainability would’ve allowed the repair to be completed faster, and the truck would’ve been back on the road sooner.

That’s the gist of RAM for maintenance teams to understand, but let’s dig deeper.

RAM Acronym, Defined

Let’s discuss each component of the RAM acronym separately to fully grasp how the concept can be factored into maintenance planning.

What Is Reliability?

Equipment reliability measures how consistently an asset performs its function without failure under specific conditions over a specified period. It’s tracked using metrics like mean time between failure (MTBF) and mean time to failure (MTTF).

The goal of doing a reliability analysis is to identify room for improvement in efficiency and minimize the frequency of failures through effective maintenance. For example, suppose you have two conveyor belts at your manufacturing facility. One operates for 500 hours without breaking down, while the other one requires repairs every few days. The first belt has higher reliability. There may be various reasons for this — the first conveyor belt might be manufactured using better quality materials or it’s maintained by a different technician who performs thorough maintenance on time.

If the cause is not apparent, techniques like failure mode and effects analysis (FMEA) or fault tree analysis can help.

What Is Availability?

Availability is the percentage of time an asset is operational and available for use, considering both equipment downtime due to failures and planned downtime.

Here’s how availability is calculated:

Availability = [Uptime / Uptime + Downtime] x 100

Tracking asset availability is equivalent to tracking its uptime (or downtime). It’s critical because to maximize your ROI on those assets, you need to maximize their operational availability and efficiency.

Suppose you have machines A and B that have the same job in the assembly line. They were purchased together using similar procurement methods and are from the manufacturer. However, machine A’s availability is 90 percent, while machine B is available for production only 65 percent of the time.

This information can inform your maintenance strategy. If machine B keeps breaking down because of a specific reason, the maintenance team can perform maintenance more frequently or repair the asset to increase availability and other performance metrics like overall equipment effectiveness (OEE).

What Is Maintainability?

Maintainability refers to how quickly and easily an asset can be restored to normal operation after a failure. Factors like repair time, access to spare parts and complexity of maintenance tasks are key drivers of an asset’s maintainability.

Mean time to repair (MTTR) is commonly used to conduct a maintainability analysis. A high MTTR translates to more downtime, which is a major concern among manufacturers. For context, downtime can cost manufacturers in the automotive sector up to $695 million a year.

Why It’s Important to Analyze Them Together

All three factors offer insights into an asset’s overall performance and efficiency. Focusing on any one element while disregarding others can lead to suboptimal outcomes. Here’s a quick overview of why analyzing them collectively is critical:

• Holistic performance optimization: Reliability, availability and maintainability are interconnected. High reliability reduces failures, maintainability ensures quick recovery from failures, and availability reflects the combined impact of both.
• Balanced decision-making: Improving one aspect often impacts another. For example, using robust but complex components might enhance reliability but increase repair time. Analyzing RAM together helps balance these trade-offs.
• Cost-effectiveness: RAM analysis helps identify cost-effective maintenance strategies by minimizing failure costs, downtime and repair expenses. For example, investing in preventive maintenance improves reliability, but excessive maintenance costs could outweigh the benefits without RAM analysis.
• Safety and compliance: System reliability reduces the likelihood of failures that could compromise safety or violate regulations. High availability ensures critical systems are functional when they’re needed. This is especially important in industries like aviation and healthcare, where poor RAM performance can lead to catastrophic failures.
• Long-term asset management: RAM analysis supports better planning for asset replacement, upgrades and resource allocation. This ensures equipment remains functional and cost-effective over its lifecycle.

Benefits of Performing RAM Analysis

RAM analysis offers three key benefits:

• Improves productivity: Increasing reliability reduces failure events, while maintainability shortens repair times. At the same time, availability metrics highlight bottlenecks and help optimize production schedules. Collectively, these factors drive up productivity.
• Decreases maintenance and operation costs: Identifying reliability-related issues allows you to deploy preventive measures instead of more expensive reactive maintenance strategies. Similarly, improved maintainability ensures faster repairs, as systems are designed to be easier to service with accessible parts and straightforward processes.
• Increases profits: Improved productivity, lower maintenance and operational expenses, and high system availability translate to increased profits.

When to Perform RAM Analysis

RAM analysis is most commonly performed during the asset or system design phase. However, its value extends far beyond the blueprint stage. It can and should be revisited throughout an asset’s lifecycle to better understand its performance, predict failure rates and optimize its lifespan.

For example, you can perform RAM analysis after installation to validate the theoretical reliability and availability estimates against real-world conditions. You can also perform RAM analysis before upgrading or replacing the asset to determine whether to repair, upgrade or replace the asset entirely.

Instead of viewing RAM as a one-off analysis tool, look at it as a periodic evaluation methodology. Here are four key factors why repeatedly performing RAM analysis is critical:

• Operating environment: Assets operating under extreme temperatures or corrosive environments may fail sooner or require unique maintenance strategies. That’s why they warrant more frequent RAM analysis.
• Operator training: Poorly trained operators can unknowingly cause excessive wear and tear to detect minor issues before they escalate. RAM analysis helps you identify whether and to what extent human factors are affecting asset or system performance.
• Maintenance strategy: The frequency and type of maintenance (like, say, a corrective maintenance approach versus a predictive maintenance one) have a direct impact on reliability and availability. Periodic RAM analysis can guide adjustments to your maintenance strategy for better outcomes.
• Quality of spare parts: Using subpar spare parts can diminish reliability and increase downtime. This undermines your maintainability efforts. With regular RAM analysis, you can identify whether part quality is affecting asset performance.

Example of RAM Analysis

RAM analysis is one of the most critical steps in designing an aircraft engine. It ensures these engines operate effectively with minimal downtime or failures. It’s not just about efficiency. It’s about safety, performance and reducing operational costs.

Take the Pratt & Whitney PW1000G engine for example. This engine, part of the Geared Turbofan (GTF) family, is used in modern aircraft like the Airbus A320neo and exemplifies how RAM principles shape advanced engineering.

During the design and testing phases, the systems engineering team relied on extensive RAM analysis to identify potential failure points. This allowed them to refine components and systems to achieve high reliability and to design an engine that delivers consistent performance across thousands of flight cycles.

The engine was designed keeping in mind that it could be easily inspected and serviced during routine maintenance, reducing disruptions to airline schedules. The result? High availability and minimal downtime.

Engineers also focused on making the PW1000G highly maintainable, with modular components that technicians can replace efficiently. These design considerations speed up maintenance, keeping aircraft in the air where they belong.

How a CMMS Can Help With RAM Analysis

RAM analysis involves tracking multiple maintenance tasks and performance metrics. Things can become overwhelming rather quickly, especially if you manage data and processes the old-school way.

That’s where a computerized maintenance management system (CMMS) like Coast comes in. With Coast, you can:

• Streamline maintenance tasks: Plan, schedule and track maintenance activities.
• Centralize monitoring: Log critical reliability data to identify trends and predict failures more easily.
• Collaborate: Keeps your entire team in sync with Coast’s mobile-friendly interface.
• Drive informed decisions: Generate detailed reports to analyze asset performance, helping you make data-backed decisions to improve reliability, availability and maintainability.

Looking to fast-track RAM analysis? Check out Coast’s CMMS for faster, more efficient RAM analysis.