Waste is anything that does not add value to a product or contribute to the final transformation of a product. Waste drives up costs, cuts into profit and can be harsh on the environment, so manufacturers everywhere regularly seek ways to eliminate waste. One way manufacturers are improving productivity and eliminating waste is by using the Lean method known as the 6 big losses in manufacturing. The idea is that the most common and impactful losses in manufacturing come from three main areas and are categorized into six types (thus six big losses). In this post, we’ll explain what you need to look for and how to eliminate these losses.
AVAILABILITY LOSS TYPES
Equipment failures or unplanned stops. Some unplanned stops may be acceptable. Tooling breakdowns, unplanned maintenance, shortages of operators, parts or materials are all examples of downtime due to unplanned stops and equipment failures. First, you should define how long the stop can be before it should be addressed. For example, you may decide an unplanned stop that is five minutes or longer needs to be documented with a reason. Use Andon lights tied to a platform such as Shop Floor IQ to track all stops and their reasons. Do a Root Cause Analysis using the 5 Whys to determine what is causing them, fix and prevent them from reoccurring.
Setup, adjustment, or planned stops. Although these are planned events, there should be a target time for completion to reduce this type of waste. Changeovers, tooling adjustments, setup, cleaning, planned maintenance and quality inspections are expected downtime, but should be minimized. Using a platform such as Shop Floor IQ, you can create rules linked to your timers that will help to identify where and when target times are not being met. Use the Single-Minute Exchange of Dies (SMED) method to address these types of losses.
PERFORMANCE LOSS TYPES
Minor or short stops. Minor stops are the most preventable loss, but they are also often the most overlooked because they seem like no big deal since they usually last for under two minutes. Product flow obstruction, misfeeds, incorrect machine settings, sensor issues (blocked or misaligned) and quick cleanup are common reasons for short stops. Using your shop floor platform, you can get insights into common statuses with analytics that track historical Andon states, then do Gemba Walks to explore the short stops so that you can implement standard practices to eliminate them. During a Gemba walk, leadership gets out of the office and goes to the shop floor to observe and gain understanding of manufacturing issues by talking to employees. To overcome employee resistance and ensure collaboration, the focus is on evaluating processes, not the workers’ personal abilities.
Asking the following questions can facilitate a successful Gemba walk:
- What are you doing now?
- Is there an established process for this work? Is it documented?
- What challenges do you face with the process?
- Why do the challenges exist? How do you find their root cause?
- How can you fix them?
- Who do you speak with about challenges that you identify?
Reduced speed. This type of loss can be attributed to both human and technical elements such as dirty machines, poor lubrication, substandard materials, worn equipment, inexperienced operators and environmental conditions. If the issue is labor productivity, use visual displays to help employees identify and monitor conditions, so they will be able to address problems that aren’t easily noticed. Production pace timers such as the one shown here are commonly used to help operators pace their current cycle to complete tasks on time.
QUALITY LOSS TYPES
Startup Rejects. Startup rejects happen during startup operations, prior to standard operations. Start up losses are often caused by inefficient changeovers, incorrect settings, long warm-up cycles, and equipment wear. While losing product is often part of the process of getting a line up and running, you can reduce waste by gaining greater visibility into the startup conditions. The count up timer shown here has dispatch queues set up, so a supervisor or technician can be immediately alerted to problems that slow production. After determining the reasons for startup rejects, develop and use standardized practices to reduce this type of waste. Standardizing the work creates discipline and good habits and includes documenting the procedures. This will reduce variability, make it easier to train new operators, and provide a baseline for improvement activities.
Production Rejects. Incorrect settings, improper setup and operator errors often result in scrap or reworks. Poka-Yoke, or “mistake proofing,” draws attention to human errors, and prevents and corrects them as they occur in an effort to eliminate defects. Here are the six methods to use for mistake proofing:
- Eliminate the error by redesigning the product or process so that the problem task or part is no longer necessary.
- Prevent the error by redesigning the product or process so that it is impossible to make a mistake at all.
- Replace the existing process with a more reliable process.
- Facilitate the process by making it easier to perform tasks.
- Detect and alert that an error occurred so no further processing occurs and the employee can quickly correct the problem.
- Mitigate the damage by minimizing the effects of errors.
- A commitment to continuous improvement will help bring production rejects to your attention so that you may take corrective action to eliminate them.
Eliminating the 6 big losses in manufacturing does not happen overnight. It takes a commitment to continuous improvement from the shop floor to the top floor. It’s an iterative process that never ends, but always improves. For help getting the right insights into your shop floor so that you can identify and reduce losses, get a free trial, or contact us to talk about your needs.