Machine Uptime

What is machine uptime?

Machine uptime is defined as the time a piece of machinery was available and operational in a given time period. 

It gives us a sense of how reliable a machine is — a high machine uptime indicates high machine reliability and vice versa.

Table of Contents

How to calculate machine uptime?
Example of low equipment uptime
Benefits of high equipment uptime
Five proven ways to maximize machine uptime
High uptime = good time

How to calculate machine uptime?

The opposite concept of machine uptime is machine downtime. 

When you have the numbers for one of those metrics, calculating the other one is trivial. You just need to subtract the figure from 100. 

The equation to calculate machine uptime is as follows:

Machine downtime is easier to observe and record. Due to this fact, the common methodology is to calculate machine downtime and subtract it from 100 to get the figure for machine uptime.

Machine Downtime = (Number of seconds machine was down / Total number of seconds observed) *100

Machine Uptime = 100 – Machine Downtime

Example of a machine uptime calculation 

You are observing one of the conveyors in your facility. If the machine was down for 30 minutes in a window of 12 hours you were observing, you can calculate its uptime by inserting the figures into the equation above.

Machine Downtime = (30*60)/(12*60*60) *100 = 4.17%

Machine Uptime = 100 – 4.17 = 95.83%

Therefore, in our example, the observed conveyor had the uptime of nearly 96%.

Example of low equipment uptime

In order to avoid production interruptions, your machines have to be available and operational throughout the production cycle. 

The production consists of multiple processes done in a sequence. When a machine experiences unplanned downtime, the processes that are upstream and downstream from the failed machine are affected.

Let’s say a production process involves five steps in this sequence: 

1. Cutting
2. Machining
3. Joining
4. Polishing
5. Quality check

The machine required for the joining phase of the production is experiencing failure. The polishing and quality check stations remain idle because they can perform their tasks only on the materials that have gone through the joining process.

On the other hand, the cutting and machining stations are still operational, so the inventory gets piled up. 

The failed joining machine caused a bottleneck and a delay in the production process. The result — a capital and operational efficiency loss.

Benefits of high equipment uptime

As reference in the example from the last section, high machine uptime leads to:

• More reliable and predictable production schedule
• Improved productivity
• Reduced unscheduled downtime
• Lower cost of operation
• Lower maintenance workload and costs

Remember, reliable machines ensure your production processes run smoothly and without significant delays.

Five proven ways to maximize machine uptime

There are various reasons for regular equipment failures in production facilities — poor maintenance, operator error, equipment or tool failure, etc. 

In order to maintain stable production, you have to find ways to increase uptime for critical equipment. Here are some ideas to get you started.

1. Choose your machines and parts wisely 

When procuring machines for your production facility, machine uptime has to be a major factor to take into consideration. In other words, choose your OEMs and vendors wisely.

When making purchasing decisions, opt for high-quality machines from reputed vendors.

Let’s say you need to drive a conveyor in your factory. You can pick between a magnetic drive and a drum motor. Both will accomplish the same purpose, but drum motors experience far more maintenance issues compared to magnetic drives.

These are the kind of choices you’ll have to make in order to maximize the uptime of your machine. The same decision process applies to procuring spare parts.

2. Implement condition monitoring and predictive maintenance

Condition monitoring is employed to supervise the operating characteristics of a machine. It can help you determine if a machine is working as expected.

Modern machines used in production are Internet-enabled, which allows you to measure, collect and record sensor data in a digital format.

If a machine is not working in the ideal state, the sensor data makes it much easier to identify the root cause of the problem, and forecast a potential machine failure in the future.

Condition monitoring and predictive maintenance are maintenance strategies that help reduce the rates of unexpected machine breakdowns, helping you achieve higher machine uptime.

3. Use Problem-Failure-Action (PFA) codes

Despite the extreme care you take, every machine will eventually fail. At that point, you’ll need to take reactive maintenance actions to bring it back online. 

PFA codes are short hands to easily identify the problem, failure, and action to be taken: 

• Problem codes indicate the problem faced by the machine. 
• Failure codes determine how the problem has manifested. 
• Action codes determine the maintenance action that needs to be performed. 

When you use automation with strong protocols for PFA codes, the problem and failure code automatically provide the action code corresponding to it.

Let’s assume we have a problem code P112 which indicates overheating. Failure code (F213) determines the problem has manifested because of coolant leakage. Automatically, the action code (A134) dictates the need of sealing the coolant chamber (maintenance action).

An example of reliability codes for a blower, fan, and pump. Source: Swain Smith

PFA codes are just one of the ways to reduce the mean time to repair (MTTR) and increase equipment uptime. Other options you should take into account are:

• Proper training of your maintenance technicians
• Creation of standard operating procedures (SOPs)
• Optimization of spare parts and inventory management process so maintenance actions do not get delayed due to lack of inventory

4. Equipment redundancy

Equipment redundancy is a reliability engineering methodology that improves machine availability and reliability. 

Imagine a scenario where two identical machines perform the same process simultaneously. When one of the machines fails, the other is ready to take over the entire load. 

The aim of equipment redundancy is not to increase the uptime of each machine, but to increase the uptime of the entire system/production process.

5. Utilize a CMMS

 A maintenance program is an important factor in keeping a high machine uptime. 

Manually coordinating and managing all the maintenance activities in a facility, in real-time, is nearly impossible. However, with a modern CMMS system, it becomes perfectly doable. 

With CMMS you can:

• Create, assign, and track maintenance work orders
• Provide storage and access to maintenance manuals, checklists, and standard operating procedures (SOP)
• Store all maintenance and machine data for reference and analysis
• Track and store condition-monitoring data
• Create and track KPIs and a maintenance schedule for all equipment
• Perform predictive maintenance

In other words, CMMS makes sure that all maintenance processes that impact machine uptime are finished on time, and up to the required standard.