In order to improve productivity and efficiency in manufacturing, you must decide where and how to spend your valuable time. Focusing too much on wasteful processes not only makes the shop floor unproductive but also negatively impacts employee satisfaction, costs, and customer experience. A Yamazumi chart can help you visualize activities that are wasteful and eliminate them.
With insights from a Yamazumi chart, you can allocate resources more strategically, spot bottlenecks, and carry out improvements wherever required. Let’s delve deeper into the chart, its components and benefits, how to create one, and more.
What is a Yamazumi Chart? Definition and Key Elements
As per the Yamazumi chart definition, the tool is essentially a stacked bar graph that indicates the time consumed by different tasks or work processes. In a Yamazumi (or ‘to stack up’ in Japanese) graph, every bar denotes a process step.
Hence, as a process analysis mechanism, this chart helps you break down and display how long it takes machines and workers to complete various activities. This is also called cycle time. Let’s explore the key elements:
- Axes
X-axis: Indicates steps of a process, operators, or workstations
Y-axis: Indicates different tasks’ cycle times
- Activity or Task Category
Value-Added (VA): Tasks that have a direct contribution towards the product
Necessary Non-Value-Added (NNVA): These activities, while needed, don’t add value
Non-Value-Added (NVA) or Waste (Muda in Japanese): Wasteful activities that must be eliminated
- Stacked Bars
Every bar indicates a workstation or process step
Blocks inside a bar denote individual tasks (they are stacked to visualize cumulative time taken)
- Color Coding
To differentiate categories of tasks and simplify interpretation, multiple colors are generally used (green for VA, orange for NNVA, red for NVA)
- Target Cycle Time
This is represented through a line and helps in detecting imbalances or areas that need improvement or optimization
The Role and Benefits of Yamazumi Charts in Factories
The importance of a Yamazumi chart lies in the fact that it helps you ease the job for everyone on the factory floor while enhancing output. Simple yet insightful, this tool aids in visualizing work distribution, optimizing workloads, and making processes more streamlined.
Key benefits include:
Drives Line Balancing
Yamazumi graphs or workload distribution charts pinpoint work imbalances by visually representing the cycle times of various process steps. This means you can compare workloads across workstations, machines, operators, or activities, and rebalance the line if required.
In other words, you can quickly spot which process step requires optimization to ensure customer demands are met punctually and consistently.
Lowers Costs
With Yamazumi charts, you can effortlessly spot delays, bottlenecks, or anything that is consuming time unnecessarily. Consequently, you can do away with tasks that don’t add value, reduce the costs associated with them, and devote more time to activities that add value.
For example, you can reduce waste in terms of excess inventory, defects, underutilized talent, excessive processing, and so on.
Improves Communication and Planning
The organizational information flow across teams and team members gets better with Yamazumi charts. This is because all stakeholders can quickly and effortlessly see which tasks are most time-consuming or tedious and take due action.
For leaders, using Yamazumi graphs can help in planning process steps more intelligently. You can even anticipate problems before they crop up and adopt preventive measures.
Encourages a Continuous Improvement Mindset
Yamazumi graphs enable employees to measure and assess their performance on a regular basis. This automatically establishes a mindset of continuous improvement or kaizen. Your staff will constantly question the current process, stay alert about any gaps, and will think creatively to add more value.
How to Create a Yamazumi Chart (Step-by-Step)
The following steps are essential for putting together a Yamazumi chart:
1. Collect Data
Start by understanding how a process flows from end to end and make a list of every task or activity that occurs in the appropriate order. It will determine the sequence of tasks on the chart’s X-axis. Then for every task, note the cycle time with the aid of digital tools or a stock watch.
2. Divide Activities into Categories
In this step, you need to categorize tasks under these heads – VA, NNVA, and NVA.
- Valued-Added (VA)
Identify activities that are directly essential for satisfying customer requirements. Such tasks should be the ones that the customer deems valuable and is ready to pay for. For example, custom painting a product or machining a product part as per consumer specifications is a VA task.
- Necessary Non-Value-Added (NNVA)
While these activities don’t directly add value to the product, they are necessary for supporting the VA steps. Often, regulatory compliance, technical shortcomings, or organizational structures are responsible for the existence of NNVA steps. Machinery setup time and product quality inspections are a couple of examples.
- Non-Value-Add (NVA)
These operations or tasks consume space, time, and resources, but offer no value addition from the customer’s point of view. You need to eliminate such wasteful activities. Examples include rework on defective products, excess inventory, and waiting for machines to be available.
Categorizing activities helps you streamline processes easily as you realize where improvement efforts should be focused. Usually, minimizing NNVA tasks, eliminating NVA activities, and enhancing the efficiency of VA operations is key.
3. Generate the Yamazumi Chart
Many manufacturing businesses leverage spreadsheet tools or Microsoft Excel to prepare Yamazumi graphs. You can make stacked bar charts flexibly and even tweak the visual presentation. Advanced digital solutions are also available for the fast creation of sophisticated charts and in-depth analysis. In fact, forward-thinking businesses are increasingly leaning towards such tools.
4. Analyze the Yamazumi Chart
Study the chart you created to detect improvement opportunities in the following areas:
- Cycle Time
Across the different steps of a process, watch out for cycle time variations. If you spot steps that take significantly longer to complete than others, these might be representative of bottlenecks. On the other hand, steps with short cycle times indicate high efficiency.
- Waste
Examine every step to estimate the proportion of time spent on NVA activities. If the numbers are significant, you can reduce waste by getting rid of as many NVA activities as possible.
- Workload
Assess how work is distributed. If your process is currently balanced, cycle times across steps should be more or less similar. Major discrepancies, however, signal that some operations are not utilized enough while others are excessively burdened.
5. Optimize the Process
Make informed and data-backed decisions related to process changes after studying the Yamazumi chart closely. For instance, you might consider combining certain steps, redistributing tasks or rearranging the workloads, or altering the sequence in which operations happen. That’s not all though.
After introducing changes, evaluate the process again and create a new Yamazumi chart to assess the effect. Repeat this periodically, so you are continuously improving.
Take Yamazumi Charts Digital on Your Shop Floor
If lean manufacturing is your objective, taking the traditional route (spreadsheets, physical boards, sticky notes, etc.) with Yamazumi charts is not the way to go. Using a digital solution instead will benefit you. Here’s why:
- Updates in Real Time
Tasks and cycle times can change every day in a dynamic environment. And a digital system will make sure the Yamazumi chart gets updated in real time with relevant data. This means, you can use the latest information to make the best decisions.
- Accurate Data
There is no room for human mistakes when you take Yamazumi graphs digital. The software can automatically obtain data on cycle time and performance from other systems and feed them into templates of your choice to churn out accurate charts.
- Better Visibility and Collaboration
Multiple teams can access, read, and analyze digital charts from anywhere and anytime. This not only improves cross-team visibility, but also makes information exchange and collaboration easy.
- Proactive Planning
You can plan for different scenarios with digital charts through simulation. Instead of reacting to a problem after it crops up, you can find out what might happen if you add another operator or machine to a process step, for instance.
- Historical Tracking
While physical Yamazumi charts cannot store past data, digital ones can do so. This means, you can analyze trends, spot patterns, investigate root causes behind problems, and check if process changes are actually working in the long run.
- Improved Customization and Visualization
With digital tools, it is possible to customize Yamazumi charts in different ways in line with your specific needs. Besides an interactive dashboard, you can expect different templates, filters, color codes, etc.
The Value of Yamazumi for Continuous Improvement
Continuous improvement is the backbone of lean manufacturing. With Yamazumi charts as a visual tool on the shop floor, you can easily spot and address work imbalances, eliminate waste, control costs and improve communication and planning.
Since it’s possible to regularly monitor process efficiencies and employee performance with Yamazumi, you can introduce improvements continuously, maximize value added activities, and save time and resources.
And with fabriq’s digital solution, making the most of Yamazumi charts on the shop floor is extremely convenient. From customizing graphs, ensuring data accuracy, and receiving real-time updates to planning proactively and studying trends, there’s much you can do.
Are you ready to balance workloads and boost efficiency on your shop floor? See how fabriq helps you take your Yamazumi Chart digital with real-time data, collaboration, and continuous improvement insights.
