Customer satisfaction hinges on delivering quality products, consistently and on time. And where possible, most manufacturers must initiate production runs as quickly as possible to meet and exceed the clients’ expectations.

However, employees and machines cannot function on a non-stop basis. Instead, machines need to be maintained, workstations require regular cleaning, and employees need rest. This is where changeover time comes in.

What is changeover time?

Changeover time refers to the period from when the last product rolls off the line in a given production run to when the start of the next run begins. It’s important to note that changeover includes the time between the last and first items that meet the relevant quality specifications as required by the client.

In many instances, manufacturing businesses use the changeover to swap parts, clean machines, and prepare them to handle the next production run.

With this in mind, it makes business sense for manufacturers to reduce the changeover period as much as possible to maximize production efficiency across their operations.

In many scenarios, changeover time and set-up time are used interchangeably. However, they do differ. Set-up time is but a component of the relatively more comprehensive changeover process. In other words, set-up time belongs to the changeover set that primarily involves clean-up and start-up.

How to measure changeover time

To effectively measure changeover time, a supervisor must observe production processes and track the time between the final action of a given production run and the beginning production process of the subsequent run.

In some instances, manufacturers will record their production runs enabling relevant supervisors and managers to track changeover time if they aren’t present for it in real-time.

Benefits of reducing changeover time

Reducing changeover time in a manufacturing facility enables businesses to maximize their productivity, increasing the number of units produced in a given day.

Changeover time can be classified as ‘Waiting’, one of the 8 types of waste in lean manufacturing that should be reduced in order to increase production value.

How to reduce changeover time effectively

As earlier discussed, a shorter changeover time enables manufacturers to maximize uptime and worker productivity in a given day. Furthermore, it reduces waste caused by downtime, significantly lowering production costs.

To reap these benefits, manufacturers in the modern era should consider taking the following steps:

1. Evaluate your current changeover process

Before implementing actions to reduce the changeover process, you should analyze your existing protocol. This can help you identify areas within the current process that require optimization to minimize the time between successful production runs.

Analyzing the current process usually entails identifying the machines that require preparation for the subsequent run cycle. Additionally, this step also documents the various sub-processes carried out by personnel to ensure that machines and production lines are ready for the next run.

With a base representation of the current process, manufacturers can then proceed to implement the SMED method.

2. Implement the Single-Minute Exchange of Dies (SMED) method

As the name implies, single-minute exchange of dies refers to cutting the changeover time down to single-digit periods of time. In other words, the ideal duration between the two successful production runs should ideally come down to less than ten minutes.

SMED requires a manufacturer to have intimate knowledge about the various granular tasks that make up the given production process. Additionally, manufacturers benefit from having the ability to monitor all relevant machines in real-time. After all, detailed knowledge allows you to identify the particular areas in need of optimization.

Here’s what SMED entails:

  • Divide the changeover process into various discrete steps to better understand and visualize the protocols.

  • The protocol comprises internal and external portions. The externals are tasks that can be executed while the machine remains operational, whereas the internal elements are tasks that can only be performed when the machine is turned off.

  • You should then identify internal process elements that can be optimized and turned into externals. In other words, analyze internal sub-tasks and evaluate if they can be executed while the machines run. This analysis is often more streamlined using digital tools with real-time input from machines on the shop floor.

  • The remaining internal processes can then be streamlined with connected digital solutions to ensure that execution takes the least time possible.

3. Establish standard changeover protocols

In many instances, employees may not receive standardized instructions to guide changeover protocol implementation. As such, changeover times can differ greatly because employees can clean up, set up, and start up a new production run in different ways.

Therefore, it’s prudent for managers and supervisors to craft standard operating procedures (SOPs) to guide the changeover process.

The SOPs should contain standardized instructions on how to execute the process. They should also outline and highlight the standard settings to which relevant equipment should be tuned or calibrated. The same applies to the ideal real-time metrics originating from the machinery.

With these in hand, employees know what to expect when it’s time for a changeover.

Reduce the amount of time between production runs with Tulip

Learn how you can improve production efficiency by eliminating unnecessary downtime during changeovers.

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