What is lean manufacturing?
The term lean manufacturing — or lean production – is a series of methods designed to improve shop floor efficiency and empower employees to increase levels of production and improve the firm’s value stream. Done well, the standard lean production model leads to a net improvement in total productivity, customer satisfaction and workforce engagement.
Origins of lean manufacturing
Lean production systems have their roots in the Japanese automotive industry and were pioneered in the Toyota production system (TPS). The TPS model has two underlying principles: continuous improvement and respect for the person.
These two themes – continuous improvement on the shop floor and respect for the person – are the cornerstones of lean thinking, helping create the flow and increased speed and flexibility in the production process that are the hallmark of a lean production system.
Over the years a variety of lean manufacturing tools have been developed in support of these themes. Deployed well, these tools can significantly reduce the time between customer demand/order and shipment. What we know today as the just-in-time approach to manufacturing cuts down excess inventories; drives reducing waste; and radically improves profitability, customer satisfaction, throughput time and employee morale.
The principles behind lean manufacturing
This approach to lean manufacturing – sometimes referred to as the Toyota Way – has been implemented across the globe by companies with often very different business cultures but all based on the four key principles of lean manufacturing:
- A long-term philosophy – to produce meaningful and lasting difference
- The right process and right products – responsive to customer demand
- People or human development: investing in, encouraging and empowering people
- Problem-solving at all levels – workforce engagement and continuous improvement
Removing no-value added to deliver high value to the customer.
The term Lean manufacturing is often defined as a systematic approach to identify non-value-added activities through continuous improvement by flowing the product at the pull of the customer in pursuit of perfection.
This is a bold goal. But the rewards can be immense. While much of the language of lean is about eliminating waste, this can only be achieved by empowering people. The two go hand in glove.
As Henry Ford noted, the hardest waste to tackle is the waste of time because it is all but invisible. Everyone on the shop floor looks busy. And the job gets done. But how many times does an operator have to turn a machine off while he or she walks across the factory floor to find a tool that should have been to hand. Unlike material waste, this waste would remain invisible until the operative felt empowered to mention it at morning briefings; and/or if a simple machine monitoring tool was fitted to the machine to shine a light on unnecessary cross-factory journeys.
An article in Industry Week titled, “The Hardest Part of Lean is to See the Waste” cites a case study in which a fabric-dyeing factory doubled its output by a simple workplace rearrangement following discussions with its staff. The reorganisation reduced the number of steps employees were making by half, and that alone was enough to double production.
Today, Ford’s purpose has evolved into one where the goal is minimising waste for the whole lifecycle of the product in a drive to more sustainable future. That means exploring how a product is designed, engineered, entered as an order, processed, delivered, assembled, installed, serviced and ultimately decommissioned. The lean production system has come full circle.
The lean management gospel identifies seven deadly sins that divert a company from the true path:
- Over production – parts must be stored, which costs money and time to move around
- Waiting – Materials frequently spend 80% of their time in the production process waiting for cutting, grinding and finishing
- Motion – too many wasted operator steps to pick up parts and pieces and seek information
- Work in progress – these unfinished parts are the one’s the customer hasn’t even paid for yet. It isn’t costing the customer a penny, but it’s costing your operation time and money.
- Defects – stop looking at scrap bins as rubbish bins; look at them as a measure of process failures! Was there some preventative measure you could have taken?
- Excess Inventory – Inventory costs can be 20% to 30% of the inventory value per year. That’s huge. Inventory is expensive, takes up precious shop floor space, and is a big drain on cash flow
- Transportation – Moving parts across factory floors opens them to being misplaced or damaged.
Avoiding these deadly sins requires a knowledge-empowered workforce that strives for continuous improvement, backed up with high-quality training and the development of new skills and competencies. Often this will mean moving away from the traditional ways of doing things, which requires good lines of communication between teams, departments and people. The idea that ‘we have always done it this way is not the way to lean manufacturing and adding customer value. For a transition of lean production to be successful, employees must be fully involved in assuming the new skills and responsibilities that bring lean principles to life on the shop floor.
This may not be easy. Research shows that 80% of implementing lean manufacturing principles is culture related. There is no quick technical fix: though good technology such as cloud based machine monitoring can oil the wheels. Without the right company culture, sustaining these changes can be an uphill struggle. Top-down, bureaucratic management only makes that hill steeper and more difficult to climb; when what is required is a team-based organisation that values, trains and supports its players.
A lean culture focuses on sustaining change through leadership, empowerment and good communication. In a lean management system, the leadership style moves from controlling the enterprise from the top to a leadership model that brings out the best in people to respond quickly to changes in customer demand. Growing this lean culture across a business should include:
- Shared vision from shop floor to top floor – joint development of lean production system
- Participative leadership style – no them and us
- Teamwork – visible team scorecards to stimulate continuous improvement
- Transparent and honest communication – to create a meaningful and lasting difference
- Collaboration – teams working together to get the job done
- Celebration and reward for high skills
- Empowered workers – with the skills/training to perform different tasks within cells
- Shared gains – rewarding and encouraging cooperation across the business.
Value stream mapping
Lean manufacturing recognises that the physical end product is just one part of a much larger value stream. By mapping the ebb and flow of this complex value stream, lean manufacturing visualises and identifies what steps in the manufacturing process add value to the customer and which ones could be eliminated to enable the product to be made more efficiently.
A value stream map displays all the critical steps in a specific process and quantifies the time and volume taken at each stage, showing the flow of materials and information as they progress through the manufacturing process. The map helps identify and remove obstacles to continuous improvement, removing nonessential activities that don’t add value to the customer.
Given the importance of time and volume to this process, the role of the machine operator along with the automated monitoring of machine data is a vital tool for those on the lean journey. Accurate and accessible data is the key to accurate value stream mapping in precision engineering supply chains.
This data supports the continuous improvement and culture change dimension of lean thinking. However, when implementing machine monitoring, it is vital that your factory’s culture is collaborative and team-based. Cloud-based data analytics can be a brilliant tool for empowering operators when it is deployed within the wider lean manufacturing ethos of respect for the person, collaboration and shared rewards.
A lean manufacturing operation recognises that its machine operators spend the most time with the machines and are probably already aware of many issues that are affecting the shop floor. Machine monitoring can help the operative’s voice to be heard which can be very empowering for them.
One of the most effective culture tools we’ve heard our customers use, is a “You said – We did” board. On the left is where the shop floor jotted down issues they had flagged, then on the right is where management jotted down what they did to resolve each issue. It seems simple but little things like this can go a long way in building trust between the shop floor and the top floor. But in at truly lean manufacturing system there is no you and we; no us and them. Just a company where all its people are engaged in a shared and common purpose. The perfection of lean manufacturing.
Machine monitoring for lean manufacturing
We created FourJaw machine monitoring to help the people and factory’s that power manufacturing achieve the best possible OEE they can. Our affordable, cloud-based, plug-and-play machine monitoring platform enables manufacturers to take their factories to the next level. Talk to us today about how we can help your factory become ‘smart’ to help you achieve lean manufacturing.