What is Downtime?
Downtime is defined as any period where production has stopped. The production is still costing money but no revenue is being generated. Within manufacturing, there are numerous causes of downtime such as machine breakdowns, workforce shortages, worker injuries, resource shortages, poor scheduling, and even planned downtime.
Some instances of downtime can be controlled while others are inherently uncontrollable. Either way, this results in employees waiting which incurs costs without any return on investment.
Downtime is a period of controlled or uncontrolled unproductivity.
There are 3 types of Downtime: Planned, Unplanned, & Idle Time.
The costs of downtime are similar to the fuel consumption of an idling engine.
To some degree, downtime is inevitable.
Businesses can use smart manufacturing technology to maintain flexibility and resiliency in periods of downtime.
The Idling Engine Analogy
For a keen understanding of this concept within manufacturing, we can compare downtime to an idling car engine.
When a car engine is idling, it is still consuming gas and developing wear and tear. But the car is not moving forward or performing the objective it is made for.
Downtime works the same way. There are still costs that are incurred. In these periods, factors such as machine depreciation costs, employee wages, and energy bills still need to be paid. On top of this, there are often costs associated with getting an operation back on schedule. The longer downtime is extended, the larger the resource costs and the greater amount of time revenue is not being generated.
From this analogy, we can see that downtime is wasteful on two levels.
Consumes Resources: Costs associated with having a facility that is not working.
Consumes Time: This is time that could have been used to produce value but is instead left inactive.
The 3 Types of Downtime
Planned Downtime happens when shut down intentionally. Most often, downtime is planned when certain actions can only be accomplished if the operation or process is not running.
Although we normally see downtime as a negative outcome in manufacturing, it can also be a necessary evil. There are times when productions need to be paused to conduct meetings with employees, implement process improvements, and/or perform valuable maintenance.
One key feature to note is that planned downtime costs significantly less than unplanned downtime.
Example of Planned Downtime
Imagine you run an aluminum extrusion operation where heated aluminum is pushed through a die to produce the desired shape. One of your machines is scheduled for a complete maintenance call. The use of this machine will need to be stopped entirely for maintenance crews to perform the required actions.
In this case, you adjust your operation so that this planned downtime creates the least amount of impact on the whole operation. Using work instruction software, you inform workers of the maintenance schedule and assign other machines within their work orders. Maintenance crews Lockout-Tagout the specified machine during low-volume periods and the operation barely feels the loss of time with the equipment.
Unplanned Downtime happens when an operation has been shut down outside of the control of the company’s leaders. It is the result of machines, processes, or people being pushed beyond their capabilities to the point of producing accidents, breakdowns, and failures.
Other serious causal factors are also included within this category. Natural disasters, workforce strikes, and employee injuries all produce unplanned downtime in an operation.
The cost of unplanned downtime is difficult to pin down due to the size and scope of every production. However, it is widely believed that unplanned downtime costs at least 10x more than planned downtime.
Example of Unplanned Downtime
In a factory producing olive oil, numerous hydraulic machines cold-press the oil from the gathered olive seeds. But there’s been a malfunction and now the press is leaking hydraulic oil all over the production floor. With the red slippery substance contaminating the production area, the operation is immediately shut down.
Clean-up crews, maintenance workers, and quality inspectors will need to perform their key actions before production can begin again. Workers are either sent home or given other tasks in the meantime, resulting in workers waiting while not generating any revenue for the company.
As we saw in our Idling Engine analogy, Idle Time still incurs costs while slowing down production and revenue. If departments of your operation are slower or faster than the production schedule, other departments are likely to be sitting idle.
Example of Idle Time
Take for instance an LED billboard manufacturer. If billboards are assembled at a rate of 5 a day while quality teams can only check 2-3 per day, then there is a clog in the operation. This requires the assembly line to slow down production to mitigate bottlenecks, resulting in the assembly team waiting for quality teams to catch up.