Idle Time – Definition, Causes, And How To Reduce It
Idle time is a phrase you will often hear in the manufacturing and workforce management space as it is closely tied to productivity.
While most people could roughly describe what idle time refers to, we will provide you with a more nuanced explanation.
In this short overview, we will explain:
what idle time is
what is its relationship to downtime
what are the most common causes of idle time
how to calculate idle time
and what can you do to reduce idle time in your organization
What is idle time?
Idle time is a period of time in which an asset is ready and available, but is not doing anything. This is why idle time is sometimes referred to as waiting time.
“The asset” we refer to can be an employee, but the term is more commonly associated with machines.
The reason why you want to understand and track idle time is because it shows the difference between your existing productivity levels and your theoretically maximal productivity levels. Simply put, every minute that your machine or employee is idle is a minute of lost productivity.
With this in mind it is not a stretch to say that, by reducing idle time, organizations can see a significant boost to their bottom line.
Idle time = downtime?
Idle time does not equal downtime. While in both cases the machine isn’t running, the key difference lies in why it isn’t running.
In the context of idle time, the machine is capable to perform its intended function but for a certain reason, it doesn’t. There are many possible causes of machine idle time like:
no input material
waiting for another machine to finish its job
different workflow and process inefficiencies
production needs to be slowed down or stopped (for reasons like inventory at full capacity)
power outages or similar technical problems that are not related to the asset in question
When we talk about machine downtime, the asset is not operational because one of two reasons:
Machine failure: Unexpected machine failure that needs to be fixed before machine can continue working.
Broadly speaking, when we talk about idle time the asset can run but it doesn’t, and when we talk about equipment downtime the machine doesn’t run because it can’t.
Because of this crucial difference, maintenance teams should track idle time and machine downtime separately.
How to calculate idle time?
Idle time represents the disparity between the time an asset is scheduled to run and how many actual productive hours have been spent.
For example, in an 8-hour shift, an employee might track 7 hours and 20 minutes of productive work. This suggests that they had 40 minutes of idle time, assuming they accurately tracked everything.
When we talk about machines, things do get a bit more complicated because you have to differentiate between when a machine is just turned on and the actually productive work it performed.
Let’s imagine that you have a machine that works for 16 hours. For the purpose of this example, let’s say it needs 10 minutes to power up, 5 minutes to shut down, has one 30 minute break for cleaning, and it is stopped for 15 minutes for a shift change.
In other words, the machine is supposed to do productive work for 15 hours or 900 minutes.
One can easily imagine a situation where a machine was idling:
5 minutes every hour waiting for input material (75 minutes in total)
10 minutes because a shift change took 25 instead of the usual 15 minutes
40 minutes because another machine in the production line had an unexpected breakdown
30 minutes to perform planned preventive work
This would all amount to 155 minutes of idle time.
Would you need to reduce it to zero? Not necessarily. Maybe those 5 minutes every hour are also needed for machine operators to take necessary breaks or to clean some things up. That being said, you would definitely want to eliminate idle time caused by unplanned machine breakdowns.
How to reduce idle time?
One question you need to ask yourself before we dive into actionable tips is something we already alluded to in the last paragraph: Do you even want to completely eliminate idle time?
This is especially important when we talk about employees. You can’t expect people to be productive every second of every day. There is a reason why most schools and universities work in 40-60 minute blocks with short breaks. To avoid burnout and actually improve overall productivity, different research suggests an ideal working block is between 50-90 minutes with a break lasting 5-20 minutes.
Things are different when we start talking about machines as it’s not like they are going to get tired, lose concentration, and make a mess. That being said, there are reasons not to push all machines to their limits either. While machines do not get tired, they do get worn out. For instance, a lot of machines have components that can reach unhealthy levels of heat if they do not have proper breaks. Sometimes, a little bit of idle time might be just what they need to cool down.
Those are specific cases you want to have in mind.
However, there is no doubt that a high amount of idle time is something that needs to be addressed as it can ruin an organization in the long run – either through lost productivity or by actually increasing costs while adding no value (this is especially noticeable in the construction and transport industries through the cost of wasted fuel from the machines and trucks that are idle).
Here are a few ways in which you can reduce idle time and improve productivity:
#1) Optimize your workflow
As we mentioned earlier, workflow and process inefficiencies are a common cause of idle time. This is why every organization should work on spotting and eliminating bottlenecks and other issues caused by those inefficiencies.
reduce the number of improvised solutions and low-quality spare parts and try to use mostly OEM approved replacement parts
use mobile CMMS to ensure that required maintenance work is done – and that it is done on time
#3) Improve information flow
This tip could easily be titled “improve communication lines” as the notion is basically the same.
There is a theory out there that the main reason corporations fail (corruption and illegal business practices aside) is because they become too stiff and inefficient. In other words, when a market forces them to change they are not agile enough to implement structural changes fast enough and they get left behind their competition.
This ties nicely into idle time. As the organization grows, the number of administrative tasks also grows because the departments need to exchange more information between themselves.
If a question has to be run through several managerial levels before an employee gets a clear answer, the employee will have a lot of idle time.
One solution for that is to, whenever possible, eliminate middlemen, clearly define who is responsible for what, and ensure direct communication channels between parties that depend on each other.
Other solutions, especially in the office environment, consist of using available software solutions to speed-up communication, automate tasks that can be automated, track work, and generate helpful reports. Coincidentally, these are all the things that a CMMS does for a maintenance department.
Identify, drill down, correct
Figuring out if idle time is a problem for your organization is often much easier than reducing it.
The main challenge is finding out the root cause of idle time. Is a machine idling because the production process is inefficient? Is it because a preceding machine in the production line doesn’t work at full capacity? Is it because low-quality input material results in more intervention from machine operators which slows the production down? Is it a combination of different reasons?
While reducing idle time is not always as straightforward as we would like it to be, the effect it can have on your bottom line makes it a worthwhile endeavor.