How Kaizen contributes to waste elimination

Kaizen is a Japanese concept that aims to deliver continuous improvement across business processes, operations and productivity. It’s a gradual, methodical process that involves all employees (not just management) that should, over time, improve efficiency and productivity.

In this article, FourJaw explores the eight wastes of lean manufacturing and how the Kaizen methodology can be applied to help reduce them. So, let’s get started; how does applying a Kaizen methodology reduce waste in lean manufacturing?

The Kaizen methodology is often considered the "building block" of all lean manufacturing methods. One of the core pillars of Kaizen is to ‘eliminate waste’ that can be applied to the '8 wastes of lean manufacturing' by encouraging them to continuously identify problematic or inefficient areas and work on resolving them. 

The 8 wastes of lean manufacturing

Understanding The 8 Wastes of Lean Manufacturing

The Kaizen method of working has the potential to remove waste from lean manufacturing production and processes. In this context, “waste” refers to any action or step in a process that does not add value to the customer, or processes that the customer does not pay for.

Originally there were seven wastes of lean manufacturing, developed by Taiichi Ohno at Toyota. These were: defects, inventory, overprocessing, waiting, motion, transportation and overproduction. An eighth waste was later added in the 1990s when this method was adapted to the Western world, to account for under-utilised talent.

Defects

Defect waste is exactly what it sounds like - defective products, machinery or inventory that lead to repair or disposal, both of which waste time and money and offer no value to the customer.

Overprocessing

Overprocessing waste refers to doing more work or completing more steps than necessary. In manufacturing, this may also include using higher precision or specification equipment that is required to do the job, using components with capabilities beyond necessary or over-engineering a solution.

Overproduction

Overproduction happens when a product (or an element of a product) is manufactured before it is needed. Often, this happens when a manufacturer may base production on historic trends in supply and demand and use it with the aim of “getting ahead”. This is sometimes called Just in Case manufacturing and can lead to a range of problems such as preventing a smooth flow of work, higher storage costs, and needing more capital expenditure to cover the production process.

Waiting

Waiting covers several factors where people or equipment are idle for one reason or another. This may sometimes be referred to as unplanned downtime. Examples of this in manufacturing include waiting for people or materials to arrive, waiting on proper instruction before starting a process, waiting for machines to be fixed, or having equipment with insufficient capacity.

Excess Inventory

Having a large stock of inventory may not seem like a waste, however, having excess inventory is sometimes classed as ‘waste’ due to the cost of holding the inventory. 
Inventory is waste due to holding costs (raw materials, WIP, finished goods). Over-purchasing or poor planning signals process flaws in manufacturing and purchasing/scheduling links. Lean Manufacturing extends beyond the factory, emphasising process optimisation and communication among support functions.

Having more inventory than is necessary to sustain steady production may result in product defects, damaged materials, inefficient allocation of capital and greater lead time in the production process.

Examples of inventory waste include:

• Delays in production
• Inventory Defects
• More finished products than demanded
• Inefficient Supply chain management

Transportation

Similar to motion waste, waste in transportation refers to the movement of people, materials, tools, inventory or products further than necessary. Inefficient factory design leads to transportation waste, triggering additional issues like waiting times, excessive motion, and increased overhead costs such as fuel, energy, and labour expenses. Poorly designed processes, or those not regularly updated, can contribute to these problems.

Solutions to effectively cut transportation waste include Value stream mapping and modifying the factory layout. This involves comprehensive documentation of the entire production flow, not just specific processes, leading to strategic changes aimed at reducing transportation waste.

Excess Motion

Motion waste refers to unnecessary movement or activities that do not add value to the production process. It involves any actions, steps, or tasks that are not essential for creating the final product but still consume time, resources, and energy. The goal of Lean Manufacturing is to minimise or eliminate various forms of waste, including motion waste, to optimise efficiency and productivity.

Examples of motion waste include:

• Excessive walking, searching for tools or materials
• Unnecessary handling of items
• Redundant or non-value-added tasks

Identifying and reducing motion waste is part of Kaizen's continuous improvement efforts in Lean Manufacturing, aiming to streamline processes, enhance worker efficiency, and ultimately contribute to the overall elimination of waste in the production environment.

Underutilised Talent

Underutilised talent refers to a situation where the skills, knowledge, and capabilities of employees are not fully utilised or leveraged to their maximum potential within the production process. It is a form of waste because it represents a missed opportunity to optimise the workforce's contributions, leading to inefficiencies and reduced overall productivity.

Common causes of underutilised talent include:

• Poor task delegation
• Lack of empowerment
• Lack of Training
• Siloed working practices (lack of team collaboration)

How Kaizen contributes to waste elimination

The Kaizen methodology, rooted in continuous improvement, plays a significant role in eliminating waste in manufacturing by fostering a culture of ongoing improvement, efficiency, and waste reduction.

Improvement

Kaizen emphasises the importance of continuous improvement as a daily, incremental process. This culture encourages employees at all levels to identify and address inefficiencies and waste regularly. A culture of continuous improvement naturally leads to reducing the '8 wastes' of lean manufacturing.

Empowerment

Kaizen places a strong emphasis on involving employees in the improvement process. Since workers are closest to the processes, they are well-positioned to identify and suggest improvements to reduce waste. By proactively involving employees and empowering them to facilitate improvements, the eighth waste of ‘underutilised talent’ is reduced.

Identification

Through Kaizen events and daily improvement practices, teams can systematically identify and categorise various forms of waste, including defects, overproduction, waiting times, unnecessary motion, excessive inventory, and underutilised talent.

Analysis

Kaizen encourages a deep understanding of the root causes behind inefficiencies and waste. By addressing the root causes, rather than just the symptoms, long-lasting improvements can be made. For example, knowing what the top causes of machine downtime are, enables operations managers to take corrective action to remove the root causes, leading to increased productivity, reduced wastage and more sustainable manufacturing practices.

Understanding the top causes of machine downtime and how they affect operations can be visualised for analysis using the data captured by machine monitoring software. 

PDCA Cycle (Plan-Do-Check-Act)

The PDCA cycle is a fundamental aspect of Kaizen. It involves planning improvements, implementing them, checking the results, and acting on lessons learned. This iterative process ensures that changes are well-thought-out and continuously refined.

Illustration of a PDCA Cycle (Plan-Do-Check-Act). 

Standardisation

Kaizen promotes the establishment and documentation of improved standards. Standardising processes helps sustain improvements and prevents the reoccurrence of waste.

Value Stream Mapping

Kaizen often utilises tools like value stream mapping to visualise and analyse the entire production process. This helps identify areas of improvement, streamline processes, and eliminate non-value-added activities.

Kaizen Events

Kaizen events are focused, time-boxed improvement activities where cross-functional teams work intensively to address specific issues. Kaizen events can lead to significant waste reduction and process improvements within a short timeframe.

Visual Management

Kaizen encourages the use of visual management techniques, such as visual controls and displays, to make waste and inefficiencies easily identifiable. Visual cues help in monitoring and managing processes effectively.

Technologies such as machine monitoring provide real-time production data which can be visualised on the factory floor, enabling machine operators and production teams to see how well a shift or job is running. 

By incorporating Kaizen principles into the manufacturing environment, organisations create a framework for continuous waste elimination, fostering a proactive and adaptive approach to improvement.