KAIZEN: Definition of Terms in Lean Manufacturing
Lean Manufacturing: Definition of terms
It is important to have a clear understanding of the terms used in any field so that communication is easier among practitioners. The same applies to lean manufacturing and lean thinking which has developed over the years into a well-respected discipline.
There are many lean manufacturing terms that are in common usage. But how many of the people who use these terms really understand them? This article explains the commonly used lean manufacturing terms in a clear and succinct manner. As much as possible, the lean manufacturing terms listed here are in alphabetical order.
A lean management device that controls operations by indicating their status and reporting when conditions are out of control.
This means giving machines the ability to detect quality problems without the intervention of humans. Also known as jidoka, autonomation has also been described as ‘automation with a human touch’. By giving machines human-like intelligence, the operator does not have to continually monitor them. This frees up the human operator to engage in other value-added activities.
A bottleneck is a condition that impedes flow of value within an organization. Bottlenecks can be machines that cannot produce at the desired rate, or material that is preventing a process from producing.
Batch and queue
A method of production where products are manufactured without consideration of the actual customer demand. A batch and queue production process is characterized by excess piles of inventory at every stage of production. This method of production is costly and leads to poor customer order fulfillment.
This the manufacturing method of placing process steps as close to each other in a sequential manner. By doing this, the throughput of the product is higher due to the enhanced flow of materials within process steps.
A one-piece-flow technique where machines are able to offload their output without the intervention of the operator. This allows the operator to man many machines at the same time and therefore increase efficiency and productivity of the process.
The production and movement of one item or small batch at a time through the complete process of manufacturing with little or no waste in between.
A supply chain strategy where items from many supplies are sorted at a central facility then re-distributed to other units within a large organization. This method of supply chain and logistics management ensures better order fulfillment due to the efficient assembly of outbound orders through the use of shipping lanes.
Production lead time
The total amount of time it takes for a complete customer order to move through the various stages of production. Production lead time is also known as throughput time and is applicable to production and well as the design phase in product development.
Non-value added activities
All those activities within an organization that consume resources but do not add value to the customer’s order. These activities add costs to the product yet are not entirely necessary to the conversion of a raw material into a finished product that can be sold to a customer.
Also known as the bullwhip effect, this is the increase in variation along different stages of the value stream. These variations are not a reflection of the actual customer demand but rather are a result of having too many decision making points along the value stream. This results in excess inventory at various stages of the value chain and yet the customer demand remains constant.
The loss of valuable production time can either be planned or unplanned. Planned downtime includes normal breaks, scheduled preventive maintenance and changeovers. Unplanned downtime includes machine breakdowns, raw material stock-outs and lack of staff.
This are devices, processes or methods that are designed to help operators avoid mistakes. Error-proofing is also known as poka yoke and can include alarms or automatic stops when an error condition is encountered.
This is a visual control method that results in an organized and productive workplace. The five ‘S’ stand for:
A root cause analysis method where one asks ‘why’ repeatedly when a problem is encountered. This process continues until a satisfactory cause of the problem is reached. The number of ‘whys’ asked is not fixed to five and any number can be asked until the root cause is reached.
A system of production where there is continuous movement of value through the arrangement of process steps in such a way that there are few stops. It involves the use of interchangeable parts, cellular layout and work balancing so as to attain flawless production.
These are the fundamental resources required by any organization in order to attain value for the customer. The four Ms are:
The gemba is the actual place where the real work in an organization is done every day. It is the location of the value added activities from the perspective of the customer. Change efforts are mainly concentrated at the gemba because it is here that the biggest gains are achieved.
Also referred to ‘genchi gembutsu’, this is the process whereby management go to the shop-floor so as to get a real feel of the source of the problems. In the process of problem solving, many managers are tempted to provide solutions from the comfort of their desks. This approach is in contrast with the lean manufacturing practice of ‘genchi genbutsu’ which encourages people to go to the source of the problem in order to get a clear picture.
This is a new production facility that offers the opportunity for the implementation of a lean manufacturing system without having to encounter the huddles normally faced in an established company. A green-field facility allows lean manufacturing to be the normal way of doing things and it is easier to start off with a lean culture.
This is the act of deeply reflecting on one’s actions so as to gain insights that can be used to correct problems and for further improvement. Hansei meetings are usually held after the attainment of key project milestones as a way of developing counter-measures to problems encountered.
Heijunka is a production technique where the variety and quantity produced over a specific period of time is levelled out. By doing this, a production facility is better able to satisfy customer demand in a cost effective manner.
Also known as a levelling box, this is a tool that is used for sorting production kanbans at the prescribed time intervals so as to achieve a balanced production throughout the day. The kanbans are placed in slots within the box that represent the time as well as the type of product to be produced. Each Kanban represents a production pitch which is the number of goods that needs to be produced within the time slot in order to meet the takt time demands.
These are meetings by teams involved in continuous improvement activities that are normally held by standing up near the progress tracking boards and reviewing any problems that may hinder the attainment of set goals. The hurdles are meant to be brief sessions that address any urgent concerns as well as suggest possible countermeasures to problems that may arise. They are also used as follow-up sessions to any issues that may have been raised before.
This is the direction in which customer demands move from receipt from the customer to the various points of processing within a provider. These points of processing are necessary in the fulfillment and the information flows in two directions - - from the customer to the provider and from the provider to the customer.