Fact Sheet - Lean Principles
Download the Fact Sheet - Lean principles (PDF 600.7 KB).
This page provides an overview of Lean tools and principles that can be applied to increase resource efficiency.
- Lean originates from the Toyota Production System; it is the continuous quest to maximise value creation and minimise waste in workplaces, supply chains and business processes.
- There are common elements in the principles of resource efficiency and the principles of Lean in that both focus on eliminating waste and enhancing value.
The Foundations of Lean
People & purpose
- A fundamental principle of Lean is getting everyone involved in the improvement process; this is the foundation of the Lean House.
- Everyone in the business should understand what the customer values about the product or process.
- They should be looking at products, services and processes and asking, "Is this adding value for our customer?"
- Anything that is not adding value is considered waste.
Stability & standardisation
- Processes are standardised, to control costs and maintain consistent quality, and stabilised so that the flow of work can be measured and controlled; this is the second foundation stone of the Lean House.
- A stable process is one where there is minimal unscheduled work, no unplanned downtime and limited rush jobs and overtime.
- An unstable process increases resource usage through rework, labour, and waste in-process.
The Pillars of Lean
Just-in-time
- Just-in-Time means we produce only what is needed, when it is needed and in the quantity that is needed. It is based on creating 'flow'.
- A customer order triggers a chain reaction that pulls materials and components through the process to arrive at each stage, exactly when they are needed, in the quantities required.
Jidoka
- Jidoka focuses on consistently achieving the highest possible quality by eliminating faults and errors as soon as they occur.
- It empowers operators to stop the line to make immediate corrections.
- It increases resource efficiency by eliminating waste created by rejects and rework.
Lean tools
Heijunka
- Heijunka is the process by which we achieve flow.
- It considers Takt Time; the rate at which a finished product needs to be completed in order to meet customer demand.
- Controlled buffer inventories are maintained for more popular items or level out fluctuations.
- Quick product changeovers, and 'balancing', levels out manufacturing of different products and influencing customer behaviour levels out demand.
- A Heijunka Box is a visual management tool that communicates to production which product is going to be made next.
KANBAN
- Kanban means "signal card".
- In a Just-in-Time system, small buffer inventory is kept to overcome bottlenecks and maintain 'flow'.
- As inventory is depleted, a signal is sent indicating that it needs to be replenished.
- In a single-piece flow system, the rate at which inventory is used is equal to the rate at which it can be replenished.
- A Kanban Board is a visual management tool that communicates current inventory levels to production and signals for replenishment.
Quci changeover (SMED)
- Quick changeover is referred to as SMED (Single Minute Exchange of Die).
- The goal of SMED is to reduce the time taken to change from one product to another in a production system to under 10 minutes (single digit).
- Changeover time is measured from the last good product off the line before shutting down to the first good product after restarting.
- SMED allows the flexibility of short runs of different product types and quick response to customer orders, reducing the need for large inventories.
Poka-yoke
- Poka-yoke means "mistake-proofing".
- It helps an operator avoid mistakes by making it obvious when a mistake has been made, or physically preventing actions that could cause a mistake to happen.
- An example is the use of blue gloves in food production; there are very few blue foods so a dropped glove is highly visible.
Andon
- Andon is an alert to let an operator know that a mistake has been made.
- Together with poka-yoke, the purpose of andon is to stop the process as quickly as possible and correct the error.
- This may be a light or sound alert and the machine may stop automatically.
- Andon prevents materials, labour and energy being wasted on products or services that will need to be reworked or scrapped.
Root cause analysis
- An investigation into the root cause for an error occurring. A Cause & Effect Diagram (also known as a Fishbone or Ishikawa diagram) or 5-Whys analysis may be used.
- Once the root cause is found, controls can be put in place to prevent recurrence.
- See the Fact Sheet on Problem Solving (PDF 876.4 KB) for more information on 5-Whys and Cause & Effect.