Identifying the types of machine downtime in manufacturing

July 19, 2024

Updated on: July 19, 2024

4 min read

In the manufacturing industry, it is nearly impossible to avoid experiencing the different types of downtime.

In 2023 ABB carried out an industry survey of more than 3000 businesses across the globe. Only 1% responded to say that they experienced no unplanned outages of critical equipment at all [1]. In contrast, a whopping 8% experienced unplanned downtime every single day. As well as this, there are instances in which the machine downtime is not unplanned.

A study by RS Industria and the Institution of Mechanical Engineers found that maintenance engineers spend an average of 18.3 hours on planned maintenance. This is in addition to, 19.6 hours of unplanned maintenance each week [2]. So, what are the various types of machine downtime that manufacturers face?

Unplanned downtime

One example of this kind of machine downtime is when a single piece of machinery or an entire production line fails to function. This happens even when it was not anticipated that it would. This idea is intricately connected to the concept of Overall Equipment Effectiveness, also known as OEE. Unplanned downtime covers periods of equipment availability, performance, or quality degradation.

Equipment Availability

This is the simplest way to think about unplanned downtime. A plant is considered to have poor availability and to be down if it is not providing the output that was expected.

Performance

A production line may still be producing an output but it may be running at a slow rate. This can be due to a myriad of issues including having insufficient resources, an incorrect configuration, or a fault. A poorly performing production process is also ineffective.

Quality

A minimal amount of products can be produced by the manufacturing line at a rate that is considered to be low. On the other hand, if these items are unable to achieve quality assurance standards, it will lead to a low overall equipment efficiency (OEE). However, as a result of this, the line becomes inoperable.

There are a wide range of operational issues that can contribute to this. Such as tool wear, subpar raw materials, process errors, and many others.

Planned downtime

Planned downtime is deliberate downtime. It is where the production line pauses or shuts down in a controlled manner as intended.

Manufacturers typically schedule planned downtime in advance.  The majority of the time, it is designed to take place during particular periods in the production cycle or when output rates are low.

This type of machine downtime may include:

Production stoppages

During a production cycle, it is possible that manufacturing machinery will need to take a break. Machines may perform this action for various reasons. A few examples of this are switching jobs, switching tools, and waiting for fresh raw materials to arrive. Or, simply waiting for an operator to inspect the part.

Inspection, cleaning, & routine maintenance

Regular maintenance of production equipment extends its life cycle. It is vital to inspect the machines for any signs of wear. In addition to this, it is important to clean them of any dust or remnants of the manufacturing process. Also, consumables should be changed or topped up regularly to ensure a high OEE.

Production schedules

It is typical for production lines to have planned downtime because the line is not required all the time. This may be due to the factory closing overnight, during holidays, or due to a lack of orders.

Product and process development

Innovation is necessary for every business if they wish to keep their current market share and grow.  Occasionally, this innovation manifests itself in the form of an entirely new manufactured product. New products can depend on new machines, tooling, and manufacturing and material handling processes.

In addition, continuous improvements to existing manufacturing activities help to increase operational efficiency and maintain competitiveness. Prior to beginning the implementation on a larger scale, all of this would require planning and testing.

Training

Training on a live manufacturing line is sometimes available for newly hired machine operators. In certain situations, it may be more effective to train operators on a line that is operating at a lower cycle time or production rate. This is particularly true when the tasks they are responsible for are complex or crucial. This requires a period of planned downtime.

Unfortunately, it is not possible to achieve zero downtime for the majority of production facilities. Most industries are subject to both planned and unplanned downtime. But, by optimising outages, you can minimise overall downtime and increase operational efficiency.

[1] “Value of Reliability”, 2023 ABB Survey Report
[2] “Industry in Motion: Maintenance Engineering Report 2023”, 2023, RS Industria