What is Changeover Time?
Changeover time refers to the period required to switch a machine, production line, or process from producing one product or task to another. For manufacturing, it typically involves activities like cleaning, reconfiguring equipment, adjusting settings, or replacing parts to accommodate the new product specifications or process requirements. As an important component of Lean manufacturing, this process aims to decrease changeover time, allowing for more flexible production schedules and improved productivity.
Moreover, changeover time is entirely dependent on the amount of elements that need to be changed in a given timeframe. For example, a production line could only require switching from one label to another, while others could need to reconfigure entire machines to proceed with the process.
The Difference Between Setup Time vs Changeover Time
When discussing changeover time, it is sometimes interchangeable with the setup process. Setup time primarily refers to the duration needed to prepare equipment, tools, or workstations for production. It is a facet of production planning and often includes tasks like gathering tools, calibrating machines, loading materials, and performing safety checks.
On the other hand, changeover time refers to the interval between production processes involved in manufacturing. It is a specific type of setup time focused on switching a machine or process from producing one product or task to another. It includes all activities required to complete the transition, such as cleaning, removing previous materials, installing new tooling, or reprogramming machines.
The key difference between the two is that setup time is a broader concept that applies to all preparatory work for production. In contrast, changeover time specifically refers to the transition between different products or tasks. In essence, all changeover time is technically setup time, but not all setup time is changeover time.
Benefits
Reducing changeover time in manufacturing brings significant benefits that improve efficiency and competitiveness. It allows for greater production flexibility, enabling quick transitions between products to meet diverse customer demands and adapt to market changes. Additionally, shorter changeover times minimize downtime and improve overall equipment effectiveness (OEE) to boost overall productivity.
By enabling quicker responses to customer needs and fostering a leaner production process, reduced changeover time strengthens a manufacturer’s ability to stay competitive while delivering consistent, high-quality products.
How to Measure Changeover Time
The formula for calculating the average changeover time is straightforward:
Average changeover time = Total time to changeover production lines / Number of changeovers
By monitoring the total time spent on changeovers across different production phases and the number of changeovers performed, the average can be calculated quite accurately. In line with this, here is a step-by-step guide to accurately capture data for changeover time measurement:
Step 1: Identify Changeover Activities
The first step in measuring changeover time is identifying the activities involved in the process. Depending on the production line, it can include tasks such as equipment recalibration, setup, adjustments, and testing.
Documenting these activities can give better insight into what the changeover process will be like and what improvements can be made to reduce the changeover time.
Step 2: Track Changeover Time
After identifying the activities involved, the time it takes to complete should be precisely measured. This can be done manually with a stopwatch or digital tools such as time-tracking software. The goal is to accurately record and capture each interval for changeovers.
Step 3: Calculate Average Changeover Time
Once all the relevant data is collected, calculate the average changeover time using the aforementioned formula. This will provide a benchmark for reference to strategize for improvements and future changeover needs.
Best Practices for Reducing Changeover Times
In addition to knowing how to measure changeover time, it is important for manufacturers to implement good manufacturing practices to improve the changeover process. Here are some practices to consider:
- Standardize Procedures: Develop standardized, easy-to-follow procedures for changeovers to ensure consistency and reduce errors.
- Implement SMED (Single-Minute Exchange of Dies): Adopt the SMED methodology, which focuses on separating internal tasks (done while machines are stopped) from external tasks (done while machines are running) and streamlining both to minimize downtime.
- Pre-stage Tools and Materials: Prepare all necessary tools, materials, and equipment in advance, so they are ready for immediate use during the changeover.
- Automate Where Possible: Invest in automation for repetitive or time-consuming tasks, such as tool changes, to reduce manual effort and errors.
- Train Employees: Ensure workers are well-trained in changeover procedures, fostering expertise and confidence in performing tasks quickly and accurately.
- Pilot Improvements on Key Processes: Test changeover reduction techniques on critical or high-frequency processes to refine methods before broader implementation.
FAQs about Changeover Times
The primary goal of changeover time is to improve productivity and adaptability of production processes. As such, shorter changeover time means less downtime for equipment and higher production rates, leading to cost savings and better customer satisfaction.
Implementing standardized work instructions and processes greatly enhances the setup for changeover time. Having clear instructions for manufacturing processes reduces confusion and miscommunication, which creates a better foundation for changeover processes. Standardization helps decrease changeover time and increase productivity across operations.
The most common method for reducing changeover time is through Single-Minute Exchange of Die (SMED). It is a process that aims to complete changeovers in less than ten minutes and streamline processes to accelerate the steps involved.
Changeover time is considered to be an essential component to achieve overall equipment effectiveness. Reduced changeover times improve equipment availability and reliability, leading to overall efficiency. Additionally, changeover time allows for more structure in the use of equipment and can prevent disruptions due to downtime.
Gabrielle Cayabyab
