How to Calculate Overall Operations Effectiveness (OOE)

Overall operations effectiveness (OOE) is a key performance indicator (KPI), measuring the total availability of manufacturing equipment in production lines. It’s a unique measurement in that it accounts for unscheduled downtime of equipment, providing a broad overview of an asset’s effectiveness in how it performs and how it is used in the production process.

OOE takes into account three key factors — availability, quality and performance. With it, teams can identify where to make improvements in the manufacturing process to help increase not only equipment efficiency but also operational effectiveness. Understanding the metric can enhance decision-making that leads to increased equipment uptime, operations time and, in turn, a higher total number of product output.

Read on to learn exactly how.

OOE Calculation, Defined 

The OOE calculation involves multiplying the three factors together — availability, performance and quality. Each is individually calculated and multiplied to give teams an OOE percentage reflecting the equipment’s overall operational efficiency.

• Availability: Accounts for planned and unplanned downtime to calculate how frequently an asset is operational and available for production. It’s measured by dividing the actual production time of the asset (when the machine is “running”) by the maximum total operations time (all regular “shift time”). Then, multiply that total by 100 to get the percentage of time that the asset contributes to production with no interruptions.
• Performance: Looks at the operational speed of an asset; it measures actual production time against the maximum possible production time. To calculate, divide actual production time by the maximum possible production time, then multiply that number by 100 to get the total percentage of maximum achieved output. 
• Quality: Measures an asset’s ability for defect-free production. To calculate, divide the amount of good-quality products by the number produced overall, then multiply that number by 100 to get the percentage that shows how reliable the asset is in creating usable products.

OOE = Performance X Quality X Availability (where Availability = Actual Production Time / Total Operations Time)

OOE vs. OEE vs. TEEP

Before we explain how OOE can work for your maintenance team, it’s important to understand how it differs from overall equipment effectiveness (OEE) and total effective equipment performance (TEEP). All three maintenance metrics assess equipment performance and use the same calculation of multiplying availability, performance and quality together, but they differ in how they define availability. Here’s an overview of the differences between the three:

• OEE: This is perhaps the most common equipment performance metric. It measures an asset’s planned production time and excludes planned downtime like breaks, changeovers or scheduled maintenance to determine an asset’s current level of productivity. Focusing more on production effectiveness during planned working hours, this calculation is used to better understand daily operations and to help address short-term inefficiencies. OEE is, therefore, calculated as Performance x Quality x Availability (where Availability = Actual Production Time / Scheduled Time).
• OOE: This measurement takes all operations time into account, including both planned and unplanned downtime. It gives teams an overall assessment of an asset’s efficiency by looking at its potential operational periods and is used in an organization’s strategic planning and long-term improvement. 
• TEEP: This is perhaps the most comprehensive metric of the three in that it considers the maximum time that equipment could potentially be available — 24 hours a day, 365 days a year. TEEP is, therefore, calculated as Performance x Quality x Availability (where Availability = Actual Production Time / All Time).

OEE gives teams a glance at an asset’s efficiency during production hours, while OOE gives them a broader view of its effectiveness, studying the entire time frame of operations. TEEP goes beyond both in showing the maximum amount of time a piece of equipment could feasibly be available.

How OOE Works for Maintenance 

Let’s take a closer look at what maintenance managers can learn about assets when calculating specifically OOE. By using the availability, performance and quality calculation, teams can gauge the effectiveness of an asset’s use, as each offers insights into its maintenance needs. For example: 

• Availability: Measures the total amount of time that an asset is operational. A low availability score shows that an asset is failure-prone and requires frequent repairs. As a result of these breakdowns, replacement parts get used quickly and aren’t always readily available, creating delays. Tracking availability helps maintenance teams identify failure trends, manage parts inventory and improve scheduling for preventive maintenance.
• Performance. Calculates an asset’s operational speed during its operational time. A low score indicates that an asset’s preventative maintenance tasks are deficient. Evaluating this metric helps determine if these tasks need scheduling or thoroughness adjustments.
• Quality: Measures output consistency. A poor quality score may reveal inconsistent maintenance methods that cause the asset to have slow cycles below expected outputs. This metric allows teams to standardize maintenance processes further so that the asset consistently meets output quality standards. 

How to Improve OOE 

Benchmark scores in OOE are standard across industries. A score of 100 percent indicates perfect production — the asset manufactures quality parts as efficiently as possible with no stoppages. A score of 85 percent is considered good or “world-class” and is a score many companies hope to achieve. A 60 percent OOE score is average and signals room for improvement in the maintenance process. A score of 40 percent or less is low, and actions must be taken to increase it immediately. To improve OOE scores, team leaders must: 

• Foster communication and collaboration: Strengthen or increase communication across departments, teams and management colleagues to share insights and goals. 
• Incorporate preventive maintenance: Preventive maintenance tasks are crucial to reducing unplanned breakdowns and extending asset lifespan. Maintenance tasks should be scheduled and performed regularly.
• Train maintenance staff: Maintenance technicians should receive continual training to improve their skills and learn effective maintenance methods.
• Enhance quality control: Improving quality control processes reduces an asset’s defects and allows it to maintain a consistent output.
• Use real-time monitoring: Teams that use monitoring tools can gather real-time insights into an asset’s efficiency.
• Focus on continuous improvement: Whether or not teams use monitoring tools, they should review asset performance data regularly to help them identify needed improvements.
• Implement a CMMS: By using a computerized maintenance management system (CMMS), team managers can centralize asset data and automate maintenance task scheduling and tracking.

Example of Using OOE 

So, how exactly does OOE play out? Let’s take a look at a huge company like General Electric (GE), which applies OOE principles across its operations, particularly in its manufacturing and service divisions. In its GE Aerospace division, the company collects data from multiple sources — equipment performance, labor productivity and process flows — to get a bird’s eye view of its overall operational landscape and a general idea of what areas need improvement. 

Through these analytics, GE identifies bottlenecks in its assets that might slow down production, disrupt workflows or negatively impact efficiency. This data also helps teams refine maintenance schedules so that assets are serviced optimally to prevent unscheduled downtime and production stoppages. 

One of the strategies in GE’s approach is predictive maintenance — which allows the company to anticipate an asset’s maintenance needs before issues occur. By using predictive maintenance tools for condition monitoring, GE can track assets in real time to avoid breakdowns and costly repairs — and ensure that assets remain highly reliable and continuously operational. 

How Coast Can Help With OOE 

Coast’s CMMS is a one-stop shop in helping maintenance teams with asset inventory management and tracking key data needed to achieve a higher OOE score and improve equipment efficiency. Our app allows you to streamline maintenance tasks and gives real-time access to asset history records and communication tools that keep everyone on the same page.

If optimizing resource use and reducing overall operational costs are key to your business — when is it not? — then Coast can be a powerful tool in helping you do just that.