Lean Tools

In every manufacturing process, our aim is to add value to a product that the customer will pay for. While adding value to our products, there are tasks that must be done to complete the work but don’t directly add value; set-ups and inspection, to name a few. Then there are the other activities that occur during production that are waste.

According to Lean Manufacturing principles, waste is anything that creates no value that the customer is willing to pay for. Waste is defined in terms of value therefore we can only know the waste by first knowing the value first. Waste, therefore, is relative to the customers’ needs.

How Do We Begin to “See” the Waste in Our Production Systems?

Cartons on Pallets
Knowing where the waste is in your process is a must for any manufacturing business.

We begin to investigate the value-adding steps and cycle times in our process, through a Value Stream Mapping process. Out of this process, we now understand how long the value-adding steps take and the overall lead time it takes to get a part all the way through to the customer.

We realise that there is always a BIG difference between these two times.  The difference between value-adding time and the lead-time time provides us with the opportunity to remove the hidden wastes in the value stream. The difference in times is where we can begin to focus on and discover where wastes are hidden.

The 7 Wastes

The 7 wastes (or Muda) have been defined by Taiichi Ohno, the father of the Toyota Production System, and they have become known as the 7Ws.

The original seven Muda (Wastes) are:

  • Transport (moving products that are not actually required to perform the processing)
  • Inventory (all components, work in progress and the finished product not being processed)
  • Motion (people or equipment moving or walking more than is required to perform the processing)
  • Waiting (waiting for the next production step)
  • Overproduction (production ahead of demand)
  • Over Processing (resulting from poor tool or product design creating activity)
  • Defects (the effort involved in inspecting for and fixing defects)

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In order to remind us of these concepts, Acronyms can be a very effective tool and here a few examples,

An easy way to remember the 7 wastes is TIMWOOD

T: Transportation

I: Inventory

M: Motion

W: Wait

O: Over-processing

O: Over-production/Excess-processing

D: Defects

Another easy way is NOW TIME: It’s now time to eliminate Mudas:

N: Non-Quality

O: Over-production

W: Wait

T: Transportation

I: Inventory

M: Motion

E: Excess-processing

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With the 8 wastes use the acronym DOWNTIME is a useful memory aid.

D: Defects

O: Over-production

W: Waiting

N: Non-utilized  Human Resources/Talent

T: Transportation

I: Inventory

M: Motion

E: Excess Processing

*Note this has now been expanded to include an eighth waste of “Non-utilized  Human Resources/Talent”.

What are the 8 Wastes?

Paint cans
Waste must be identified and removed if you are to make your business as efficient as possible.
  1. Defects – The simplest form of waste is components or products that do not meet the specification.  The Toyota quality achievement came with the switch from Quality Control to Quality Assurance – efforts devoted to getting the process right, rather than inspecting the results.
  2. Over-Production – A key element of JIT was making only the quantity required of any component or product. This is the main challenging point to the Western premise of the Economic Order Quantity (EOQ) upon which MRP system is built on. This defines the fixed ordering costs, built around set-up times, and thus the need to spread these fixed costs over large batches. The Toyota production system moved from long set-ups to Single Minute Exchange of Die (or SMED).
  3. Waiting – Time that is not being used effectively can only be a waste – we are incurring the cost of wages and all the fixed costs of rent, rates, lighting, and heating so we should use every minute of every day productively. The Toyota production system is focused on the reasons why machines or operators are under-utilised and set about addressing them all. Thus we have new tools for preventive maintenance, the creation of flow and the emphasis on takt time.
  4. Transportation Waste – Moving items between areas, buildings or factories incurs a cost, in energy to initiate the movement – such as the petrol absorbed by a forklift truck. However, there is much more than just the accounting costs; the movement brings other costs. Managing a factory with operations spread apart is much more difficult than when the subsequent stages are located in the same work cell adjacent to one another.
  5. Excessive Movement – Separate from the transporting of items is movement. People spending time moving around the plant or cell is equally wasteful. The time a machine operator wastes walking around in order to find a piece of tooling or spanner could be better utilised if we improve housekeeping by locating every needed in a place that is close at hand.
  6. Over Processing – A good example from my own experience relates to surface finishes requirements on the component. The original drawing required a cyclonical grinding to improve the surface finish after turning. When a new CNC machine was installed the required surface finishes could now be achieved with a finished path of the new lathe.  Thus the grinding operation was removed. A basic principle of the TPS is doing only what is needed.
  7. Excess Inventory – Now everyone understands that a key element of the Toyota production system is that a JIT production system reduces the cost of inventory. By lowering the inventory we can then see the problems in resupplying the inventory in short lead times. Thus lean is a continual process of improvement.
  8. The eighth waste – Non-utilized Human Resources/Talent – The waste of not using people to the best of their unique abilities. How can we involve everyone in developing ideas to generate improvements and new products?

Now you have an understanding of the 8 Wastes and how to identify them you can start to learn about Value Stream Maps and how to create your own Value Stream Maps to identify where the wastes in your processes. Value Stream Mapping sessions are some of the most powerful Lean tools you can use to enhance your business, it’s people and process.

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5S and a Visual Workplace – Essential for Sustaining Lean Manufacturing

5S Cleaning Stations Like this One are Just a Small Part of the Picture of Creating a Visual Workplace

Around 20 years ago, when I was first being introduced to Japanese Manufacturing techniques, one of the first tools I learned and implemented was 5s. In hindsight, I became rather enamoured with that tool and was guilty, like many, of being happy to focus just on 5S and not seeing that it was actually a small part of an overall management system.

As a result of people like me seeing 5s as “The Answer”, it has got a rather bad name among the elite of lean experts, who are dismissive of 5S (if you doubt this, try and find mention of it in a major lean conference – you probably won’t). It’s often considered being just window dressing and a bit superficial.

Making things worse, some authors and some consultants have presented 5s as “The Answer” for achieving continuous improvement in business. Huge management structures have been developed and many pages are written around what is a very simple improvement tool. Although equally TPM, Visual Management and Autonomous Work Teams have been (and still are) presented as “The Answer” and probably don’t come into the level of criticism that 5S gets.

As we all know (or should know by now), all these tools and techniques are elements of a lean management system and work best when used together in an integrated approach. In my opinion, 5S is an essential foundation element in any lean management system.

5S Matters For Three Reasons

1. Creates a standard for the workplace

Firstly it creates a standard for the workplace. Effective 5S creates an environment where the expectations of how a workplace should be organised are clearly established, with the involvement of all the people who work in that workplace.

Processes are then established to maintain and improve the standard of organisation that is achieved. By establishing a standard for workplace organisation and tools to keep improving this standard it provides an excellent platform to engage people in the discussion of work cell design and standard work.

Likewise, the routine of regular tasks and auditing required by 5S is readily extended to simple cleaning, checking and lubrication tasks, providing a platform for autonomous maintenance.

 

2. Provides the foundation for visual control

The second reason 5s matters is that it provides the foundation for visual control.

This is the use of simple visual tools and signals in the workplace to enable us to make decisions and see problems quickly. That old 5S favourite, the shadow board, is a great example as it enables us to see at a glance, what tools we have and what tools we are missing.

In my experience, effective visual control is one of the most important elements of sustaining lean. Once established and accepted by the team in a workplace, visual controls tend to be hard to “break.” This is because the use of visual control is everywhere in our world.

Lines, signs, colour coding and symbols are used everywhere our world to enable us to make decisions in almost every walk of life. When driving we all know to stop on a red light and go on a green one. We do not have to refer to anyone and can make the decision instantly. It is also the same decision whenever and wherever we see that particular control.

Visual controls are therefore part of our everyday life and a very human solution to controlling the everyday behaviour of millions of people in potentially difficult or even dangerous situations.

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Imagine for a moment a world without these every day visual controls. Chances are (unless you have effective 5s), you already know such a world, and it is the place where you work! In the workplace, it makes sense that the use of the same kind of visual controls that we see all around us can simplify our work and empower us to make everyday decisions without the need to refer to a supervisor or manager.

This important for safety (e.g. separating people from forklifts or signalling what PPE to wear), but is also very important in controlling our business processes. For example, a kanban system is usually visually controlled and relies on the materials and kanban cards being returned to the right place every time.

This Shadow Board for Punch Tooling achieves the 5S objective of improving housekeeping and standardising the workplace, but it also reduces looking time and is an integral part of reducing set up time for this machine.

A FIFO lane is designed to control the level of work in progress between processes but only works if all product is placed within the lane. A Heijunka box manages the sequence of work and allows us to see our backlog at a glance, but only works if production orders or kanban cards are returned in the correct sequence in a timely way.

To make visual control work requires a discipline that things only go where they belong and that we all follow a standard process.

An audit process is needed to check that this discipline is maintained and a process for improvement is needed to address problems.

Therefore if our FIFO system, our kanban system or production cell is to work we need a foundation process that controls the organisation of the workplace. The system for achieving this is 5s. So don’t be afraid – get out the line marking paint and the labelling machine and order some shadow boards. Expect high standards of housekeeping and maintain a regular auditing regime.

If you are to be successful in sustaining lean you need a visual workplace and you need standardisation I don’t know a better way of achieving this than 5s. However, so you don’t make the mistake that I made 20 years ago, remember that 5s is a foundation tool and there is more to a house than its foundations.

3. Standardise leadership activity to routinely improve the workplace

A red-green task board is a great tool for standardising 5S activities

The third reason is to standardise leadership activity to routinely improve the workplace. Getting the leader to walk through an area and discuss the 5s every week is very powerful. The “Manage By Exception” alternative is for managers to discuss issues with employees only there is a concern.

Routine discussion between Managers and staff ensure small problems are addressed. Join together the weekly audit with an expectation to improve and you get a work area where the area owner is actively trying micro improvements within their control.

The manager becomes accountable to the working team to consistently approach the area owners and discuss 5s and help identify improvement.

Related Content

Visit Our 5S Page

TXM Lean Minute: Top Five Practical 5S Videos

TXM Article: Setting Practical 5S Standards

TXM Article: Sustaining Practical 5S

TXM Article: Lean Starts with Housekeeping

Purchase Red-Green Task Cards and Boards (Kamishibai)

Production Flow Elements – First In First Out (FIFO)

A key part of implementing Lean Manufacturing into a Production area is understanding Flow. Flow is how parts move along the processes, between each workstation and what this looks like across the week and month.

Value Stream Map for Production Flow

The future state value stream map provides a vision for what the Production flow will look like. It defines which parts of the overall production process can flow easily. It also identifies which parts need direction and which sections need the highest level of control.

Direction Between Flow Sections

For the parts of production that need direction between flow sections but some level of balancing can be achieved, a First In First Out (FIFO) queue can be useful.

FIFO queues dictate the order of the product as it arrives in a queue for the next operation. These work especially well when two or more processes are then funneled into a single process or a department.

Establishing A First In First Out Queue

An overall analysis should be conducted when establishing a FIFO queue, to ensure that the capacity is sufficient. Capacity should be able to cope with the usual variations your factory can expect over a month of production. If one section of the process is a stand out bottleneck, other lean tools might be brought in. These tools might include set-up reduction and preventative maintenance.

Defining a FIFO area needs to include the maximum and minimum amount of product you expect. This will help to establish how much area you physically need to create this queue. It will also help in setting the limits to audit the FIFO lane.

FIFO queues need to be visual. They should be signed to explain what the queue is for, what the maximum and minimum limits are. Additionally, they should also explain who moves the product in or out and who to call if things aren’t right.

Clearly defining the process to stop production when the maximum point has been reached is critical. Everyone should understand it. If not, the benefits of a FIFO queue will be lost. This is especially true if production is allowed to continue.

FIFO Queues Need Auditing

A simple daily walk of the production process, noting the level of inventory in each FIFO area, on a standard form, is a great way to keep an eye on production. It also helps to gauge the health of the process by noting which parts are running well and which areas may need help.

Keeping a daily check of the overall work in progress over a period of time will show how well the production system is going and how good the initial analysis was. This information can then be used to further refine the production system and problem solve the areas that are preventing flow from occurring. FIFO queues are a good way to control the movement of product between machines or areas of flow.