Frequently Asked Questions on Lean Manufacturing
What is Lean Manufacturing?
Lean manufacturing, or as it is sometimes called lean production, is a production method derived from Toyota’s operating model “The Toyota Way”. The premise is to minimize waste by maximising productivity thus avoiding any non-value add activities that the customer in theory is not willing to pay for. The lean principle of Kaizen or continuous improvement is central to lean manufacturing.
What are the five principles of Lean?
- Identify value
What is it that the customer is willing to pay for?
- Map the value stream
The Value Stream is all the tasks that are carried out to produce a product or service. By mapping all these tasks it allows one to identify those that add value and those that do not.
- Create flow
In Lean management flow is how work progresses through a system.
- Establish pull
Based on customer demand.
- Seek perfection
What are the 7 wastes of manufacturing?
The acronym TIMWOOD is often used as an aide memoire to remember each of the 7 wastes.
What does TIMWOOD stand for?
TIMWOOD is an acronym that is used to remember each of the 7 wastes of manufacturing. The Japanese call it Muda.
Each letter in the acronym TIMWOOD represents one of seven wastes. The premise behind lean is that waste is any activity which does not add value to the product or service being provided to the end customer.
Transport: Unnecessary movement of product results in time wasted and materials are more likely to be damaged.
Inventory: There are different views as to whether or not excessive inventory should be included in these wastes, as inventory (no matter how much) is considered an asset. Having too much inventory however, can lead to longer lead times, damaged or defected products, and an inefficient use of capital. Trying to maintain excessive inventory means reducing available storage space and utilizing extra resources just to manage it.
Movement/Motion: Unnecessary movements are considered wasteful in that they are not adding value. Spaghetti diagrams are often used in lean to track movement and to help then with analysis in identifying unnecessary movements.
Waiting and Delays: Waiting is often an easy waste to overlook. Time that is lost due to a lull in productivity is considered a waste. This usually happens when workers need to wait on material or when production is halted for unexpected equipment maintenance.
Overproduction: Did you know overproduction can lead to other types of waste while hiding the need for improvement? When production exceeds customer demand, facilities are left with excessive inventory to store and manage.
Over Processing: A product or service that has more features or capabilities than required or expected by the company would be considered over processing. It is important for businesses to understand what they’re customer requires from the product and eliminating any tasks or processes that is not useful or necessary to those requirements.
Defects: Many consider defects to be the worst of the seven wastes. Characterized as products that do not meet company standards, these products must either be scrapped or reworked, thus adding costs to the operation but not adding value for the customer.
What is the 8th waste?
Unused talent or potential is considered to be the 8th waste. This is when the potential of an employee is not being fully utilized whether it be their talents, skills or knowledge.
How do you know if value is being added?
Ask these 3 questions:
- Is the customer willing to pay?
- What are we changing / creating / transforming to add value?
- Was it done ‘right first time’?
What is Lean Six Sigma?
Lean Six Sigma is the combination of lean principles and Six Sigma to further operational excellence.
Six Sigma aims to reduce variation and uses tools such as DMAIC and the Fishbone.
What does FIFO stand for ?
FIFO is the abbreviation for First In First Out. In lean production the idea is that the first part to enter the process should be the first part out. This helps with flow and allows for better management of inventory.
What is Continuous Improvement?
Continuous improvement is considered to be a critical element of a lean philosophy. Kaizen, a Japanese term, is often used for continuous improvement. Kaizen mean ‘change for the better’. In Lean management continuous improvement focusses on improvements to processes that add value for our customers and reduce or remove waste where possible.
As James Clear, author of Atomic Habits, puts it ‘Continuous improvement is a dedication to making small changes and improvements every day, with the expectation that those small improvements will add up to something significant’. See here for more from James Clear.
What does PDCA stand for?
PDCA stands for Plan – Do – Check – Act.
Originally used for quality control, this tool founded by American engineer William Deming was subsequently adopted for achieving continuous improvement. The idea behind the tool is that it is a never-ending cycle that strives for further improvements or refinements based on achieved results.
What is 6S?
6S stands for Safety – Sort – Set in Order – Shine – Standardise – Sustain. It’s a lean process improvement tool used to optimise the workplace environment.
What is Poka Yoke?
This is a Japanese term that means mistake-proofing. Essentially it is fail safe devices that reduce the incidence of error by the operator. For example guided-operating systems are useful devices manufacturing that can be used to reduce human error. See here for an example of how a guided operating system can be programmed:
What is Kanban?
The term ‘Kanban’ literally means “visual sign” or “visual card”. It was originally used to track production by the car manufacturer Toyota as part of its Toyota Production System (TPS).
What does Andon mean?
Andon is a Japanese term originally meaning Paper Lantern. It is a visual and/or audible communication system that is designed to alert managers and operators of issues arising in real time. The idea is that corrective action can be taken quickly to find a solution.
What does PIT mean?
PIT is short for Performance – Issues – Targets.
In Lean Manufacturing PIT meetings are often used to monitor daily progress and to highlight any issues that might be delaying the meeting of targets. These could be safety or quality issues or material shortages for example.
For more on PIT meetings see the useful booklet prepared by LBS partners.
What is root cause analysis?
Root cause analysis is a problem solving method used to identify the root causes or problems of the relevant issue. In Lean Manufacturing the 5 Whys is one such technique used to get to the root cause of the issue. Each ‘why’ forms the basis of the next question. Although called the 5 Whys the issue may take fewer or more ‘why’ questions to get to the root cause.
Another tool that is used in lean manufacturing is the fishbone diagram. The fishbone is also known as Ishikawa or cause and effect diagrams. All the potential causes leading to the issue are listed under one of six main branches of the fish skeleton (Man – Material – Method – Machine – Measurement – Mother Nature). Fishbone diagrams are useful for providing a holistic overview of where the greatest number of issues are clustered and which are having the largest effect.
For some examples of lean solutions in the manufacturing sphere click here.