Lean Manufacturing Overview

Competition in manufacturing is constantly increasing so it is important to make products as efficiently as possible. One methodology for achieving this goal is known as Lean Manufacturing. Lean is based on the Toyota Production System and was introduced to Western manufacturers in the early 90's. Lean is focused on creating value for the end customer, anything that does not create value for the end customer is wasteful and should be minimised or eliminated.

Continual improvement requires continuous change, however most manufacturing equipment is decidedly static. FlowTube is ideally suited to making rapid changes as it is fast to assemble and quick to change. Lean manufacturing also emphasises the participation of every employee in making changes, with FlowTube this is possible as it requires no specialist tools or training. FlowTube is also ideal for Lean manufacturing as it is reusable, which minimises waste.

The Causes of Waste – The 3 Ms

In the Toyota Production System there are 3 high level causes of waste:

  • Mura – Unevenness
    Unevenness in production results in alternating over-utilisation and under-utilisation, not only is this inefficient, it also frequently causes Muda and Muri.
  • Muda – Non-Value Adding Work
    Non-Value Adding work is any work which the end customer would not be prepared to pay for and is therefore wasteful.
  • Muri – Overburden
    Overburden occurs when people, machines or processes are asked to do more than they reasonably can. Overburden leads to poor quality and breakdowns, which are wasteful.

Value Adding / Non-Value Adding

One of the key distinctions in Lean is between Value Adding work [VA] – anything the end customer is prepared to pay for and Non-Value Adding work [NVA] – anything the end customer is not prepared to pay for. For example: the end customer would be prepared to pay for the actual assembly of the product because that is useful to them, however they would not be prepared to pay for scrap, paperwork or warehousing of the product because that is not useful to them.

A surprisingly high percentage of work in traditional manufacturing falls into the Non-Value Adding category and one of the main focuses in Lean is minimising or eliminating Non-Value Adding work.

The 7 Wastes

The easiest Non-Value Adding work to identify is pure waste, which can be summarised by the 7 Wastes: Defects, Over-production, Transport, Waiting, Inventory, Motion and Over-processing. By minimising or eliminating waste, significant bottom line savings can be achieved.

The 5S

One of the foundations of any Lean Manufacturing environment is 5S. While it is often over-simplified to 'workplace organisation', 5S should be a deep cultural change and result in improved quality, safety and employee engagement. 5S is short for the process of: Seri (Sort), Seiso (Shine), Seiton (Set In Order), Seiketsu (Standardise) and Shitsuke (Sustain). This process should be repeated on a regular basis for optimum results.

Visual Management

A key way of reducing waste on the shop floor is providing the right information as simply and quickly as possible. Rather than requiring an employee – any employee from janitor to CEO – to go to a computer or look up a book to find out information, it should be readily available at the Gemba – Japanese for 'the actual place'. Visual Management should be as simple and obvious as possible, ideally someone unfamiliar with the system should be able to understand it easily. Using Visual Management should make it possible to manage production and spot any problems without having to leave the shop-floor saving time and money.
(See FlowTubes Lean Display Boards)

Kaizen

Another key foundation of Lean Manufacturing is Kaizen. Literally translated from Japanese. it means “change for the better”. However, it is more commonly translated to  “continuous improvement”. While other continuous improvement methodologies focus on breakthrough projects lead by specialists,

Kaizen emphasises smaller more frequent improvements made by every employee. This approach empowers employees to make improvements and reduce waste, rather than having to rely on intermittent external intervention.

Kanban

Lean manufacturing is based on pull scheduling to achieve Just In Time production, where work is driven by actual customer purchases. With pull scheduling information flows backwards through the supply chain so that only what has been purchased will be produced. A common way of achieving pull is known as Kanban. Literally translated from the Japanese Kanban means 'signal' and in production it signals what to produce. Using pull scheduling eliminates wasteful overproduction, reduces inventory and improves cashflow.

SMED [Single Minute Exchange of Dies]

As maximising machine utilisation by producing large batches is a false economy – it causes substantial waste in the rest of the process – it is important for a Lean manufacturer to reduce batch sizes. Reducing batch sizes normally necessitates more frequent changes in machine setups resulting in un-productive time. It is therefore critical to minimise changeover time, so that overall production capacity is maintained.

A common approach for reducing changeover time is know by the acronym SMED [Single Minute Exchange of Dies], which originates from the goal of changing dies in a press in one minute.