4W1H methods

The 4W1H method is a problem solving method that helps to identify a problem. It involves asking the questions: Who, When, Where, What and How Much/How many or How. We also sometimes add the P of Why.

5 Whys

The 5 Whys method helps to find the root cause of a problem. It consists of asking the question “Why?” 5 times in order to get to the source of the problem.


5M or Ishikawa Diagram or Causes-Effects is a problem solving method that identifies the type of cause and its effects from among 5 types of causes. The 5-M branches are : Medium/Environment, Methods, Machines, Manpower, and Material.


The 5S designates an optimized storage method in 5 steps: Sort, Set in Order, Shine, Standardize, Sustain. The goal is to make room and organize your workspace to save time and productivity.

7 types of waste

The 7 wastes are the 7 elements having a negative effect on production. In English, we use the acronym TIMWOOD to retain it: Transport, Inventory, Motion, Waiting, Over-process, Over-production, Defects. .


The ABC / fmr matrix lets you clearly define the scope of your project. The ABC analysis divides products into 3 categories : – category A : 80% of your revenue – category B : 15% of your revenue – category C : 5% of your revenue The ABC / fmr Matrix adds the dimension of frequency to the ABC analysis:
– f for frequent
– m for moderate
– r for rare

Added Value

The Value-Added includes the production actions that the customer wants to pay, all that is really necessary for the manufacture of the product.


Visual warning signal linked to a preventive control system (Jidoka). Japonese translation : lamp


Autonomous Production Unit


The regroupment (cell) of certain steps of production makes it possible to reduce work in process, and therefore the production lead time, but also gives greater flexibility and autonomy in terms of production management (flow, human … .).

Autonomous maintenance

Autonomous maintenance aims to involve operators in simple tasks such as cleaning and maintaining machines. Its goal is to detect anomalies before they become breakdowns.

Batch Size

It is the number of products included in a batch.

Batch size factor

We calculate a “Batch Size factor” by dividing the total changeover time for all products to be manufactured by the time available for changeovers. (EPEI method).


Group facilitation technique to generate ideas. The main rule is not to censor other people’s ideas, but to bounce ideas off each other.

Bottleneck workstation

A bottleneck is a workstation that limits the overall performance of a workflow. He’s the one with the lowest rate in a workflow.


Process capability verifies the ability of a process to produce within specified tolerances.


The changeover defines the moment when a workstation changes from one series to another. You have to be careful because its duration can vary and be very disabling.

Coefficient R2

The R² coefficient (or coefficient of determination) is used to analyze the relationship of one variable to one or more others. The closer R² is to 1, the stronger the relationship between the variables.

Confidence interval

The confidence interval makes it possible to quantify the zone of uncertainty, at the time of a survey or a poll relating to a sample of population.

Corrective Maintenance

Corrective maintenance consists in intervening on an equipment when it encounters a problem.


The CTQ (critical to quality) are the essential specifications for the customer.


The CTS (critical to satisfaction) are the essential specifications to guarantee customer satisfaction.

Customer Demand

Customer demand corresponds to the quantities of products expected by customers over a given period

Cycle time

The cycle time corresponds to the time that elapses on a workstation between taking charge of a product for its transformation and the end of this transformation.


The time between the sales order and the delivery of a product to the customer

Delay Zone

The backlog area is the area in the Queue tool where the company is under capacity.

Delivery Date

The delivery date is the commitment that our company has made in terms of deadline towards a client.

Depth of delay

The delay depth corresponds to the delay in delivery of a given order.

Effort/Payoff Matrix

The Effort-Payoff Matrix is a tool traditionally used to prioritize an action plan. It consists of classifying each action according to its impact in terms of gains relative to the effort required to implement it.


EPEI means Every Part Every Interval. EPEI is a calculation method that lets you determine the smallest Batch Size possible to fulfill client demand by optimizing your Production Capacity. In other words, devoting all of a machine’s overcapacity to changeover.

External task

The notion of internal or external task is used in the SMED method. An external task is a task that can be carried out before the process stops, by anticipation.


FIFO, First In, First Out (or First In First Out) refers to an inventory management process where the objective is to respect the chronological order of products.


The FMEA method (Failure Mode and Effects Analysis) linked to the quality of a process, allows the criticality analysis of a process step or a process, on a product or a production flow.

Flow chart analysis

The flowchart tool is used in particular to diagnose wastes on a production line or workstations, during a Kaizen or Kaizen Blitz event for example. Several icons are used to identify the types of Value and Not Value Added (VA or NVA).

Gage R&R

Statistical tool used to measure the performance of a measurement system. Repeatable: same measurement with the same observer. Reproducible: same measurement with another observer.

Gemba Walk

The Gemba Walk consists in questioning all the employees of the factory in order to know their function and the problems they may possibly encounter. They can also submit areas for improvement to optimize production. This method is also called: the field tour.

Global Equipment Efficiency

GEE is calculated by dividing the Useful time by the Total opening Time.
Total opening time = Useful time + all wastes, planned or not!


Heijunka is a Japanese term meaning “leveling”. It is a scheduling technique that consists in smoothing the production.


Hoshin is a Japanese term meaning “compass”. The entire company must adopt the same objectives in line with the strategic vision.

Internal task

The notion of internal or external task is used in the SMED method. An internal task is one that can only be performed when the process has stopped.


Just-in-time is a method of optimizing production, which consists of reducing inventory of raw materials and finished products to zero to reduce costs and minimize lead times.


Kaikaku is a Japanese term meaning “radical change”. It is opposed to Kaizen, which is based on a continuous improvement process, inexpensive and daily.


Kaizen is a Japanese term meaning “Change for the better”. It is a continuous improvement process, inexpensive and daily.

Kaizen meeting

Kaizen meetings allow employees to come together to find solutions to the problems they face, together.


Kakushin is a Japanese term meaning “Innovation”. It is opposed to Kaizen, which is based on a continuous improvement process, inexpensive and daily.


Kanban, a basic tool for setting up a pull flow, is a signal that identifies what is needed, when needed and in the ideal quantity. It is often associated to a simple visual management (labels, color boxes, etc). It makes possible the overall control of the work in process, in a production chain and thus avoid the waste of overproduction (the worst one !). Three areas compose the calculation of a kanban stock (or loop): the red, yellow and green area.

Lead Time

The Lead time is the time it takes for a product to travel the entire production chain, from the stock of raw materials to that of finished products.

Lean diagnostic tools

Lean diagnostic tools are the tools used to analyze and measure the operation of the business. For example, the Gemba Walk, the Spaghetti Daigram or the VSM are diagnostic tools.

Level of Service

The level of service is the level of quality and speed of delivery promised and therefore expected by customers.


LIFO, Last In First Out, is an inventory management method that consists of first recovering the last products to be taken out of a workstation. It is the opposite of FIFO (First In First Out) which consists, on the contrary, in recovering the oldest products first.


Logistics refers to the entire process of transporting resources, raw materials and finished products, by logisticians

Logistic batch

The logistics batch is the quantity of product that the logisticians transport between the stock of raw materials and the workstations.

Logistics route

Logistic routes, Milk Run path allow your logisticians to work more efficiently. This consists of assigning them tours at fixed times to which they will distribute raw materials, ancilliary and finished products to the various workstations.


Maintenance keeps the machines in good working operation. Thanks to good maintenance, breakdowns are reduced and the risk of damaging the products as well as the risk of injury to operators which is essential.


Mik-run are used by logisticians during logistics routes. They fix as many wagons there as necessary: one for each additional product and another for products moving from one station to another.


The product mix corresponds to all the types of product you can produce.

MTBF = Mean Time Between Failures

MTBF = Mean Time Between Failures – Average time between to breakdown or failures – TPM Kpi’s (see TPM)

MTTR = Mean Time To Repear

MTTR = Mean Time To Repear – Average time until an equipment is repear – TPM Kpi’s (see TPM)


Characterized by waste, divided into 7 categories. See definition on the 7 types of waste.


Characterized by the variability or irregularity of a process.


Characterized by the use of disproportionate means to carry out an operation.

Non-Value Added

Non-Added Value (NVA) refers to production actions that do nothing for the product itself, such as unnecessary movement or transportation, and that the customer is not ready to pay for.

Necessary Non-Value Added

The NNVA designates the NVA which cannot be eliminated such as the recording of expense accounts for salespeople or the establishment of the company’s balance sheet.

One piece flow

A one-piece flow is characterized by the fact of producing in pull-flow, reducing work-in-process to the minimum necessary.

Opening time

Opening time = Useful time + all wastes, planned or not.

Order Portfolio

The order portfolio contains all orders already placed by customers but not yet fulfilled.

Overall Equipment Efficiency

OEE refers to the performance of a workstation or machine in the process. It is calculated by dividing the useful time by the time required (useful time + unplanned waste).

PCE = Process Cycle Efficiency

The Process Cycle Efficiency ratio indicates the percentage of added value in a production process.


Planning makes it possible to plan a production order in advance when different product references are required. You can choose the number of products to paint from one color before switching to another.

Poka Yoke

“Mistake-proofing” in English. A simple system (often mechanical) that avoids errors. The objective is to block the product as soon as possible before the error occurs.


Productivity measures the degree of contribution of one or more production factors (material factors consumed or immaterial factors used) to the final result released by a manufacturing process.


Obeya is a Japanese term meaning “Large Room”. It is the place of collaboration and animation of rituals. You can find many visual management supports where the company’s key indicators are displayed. All employees have access to this room.

Preventive Maintenance

Preventive maintenance consists in intervening upstream of the problem to prevent its occurrence.

Process Capacity Sheet

A process capacity sheet describes the process standard of a workstation, step by step.

Production Capacity

The production capacity corresponds to the number of drones that your factory can manufacture in a given time. You can improve this ability by making your factory more efficient.

Pugh Matrix

Decision support matrix, composed of several weighted criteria.

Push Flow

Management of a production flow which does not take into account the real customer demand. In general, this flow generates unnecessary stocks and some wastes of Lean.


A Queue, or Queuing, is a group of people waiting in an organized way for something. The Queues result from a demand greater than the capacity to sell an offer (a good or a service).

Queueing Management Tool

The Queuing Management Tool presents the workload per day, according to the order schedule. It includes 3 areas – a delay zone => charge> customer delay – an underload zone => load <1 day – between the two: optimal zone It allows to adjust the capacity to stay in the optimal zone


RACI is an acronym derived from the four key responsibilities most typically used: responsible, accountable, consulted, and informed. It is used for clarifying and defining roles and responsibilities in cross-functional or departmental projects and processes. There are a number of alternatives to the RACI model.


Relocation consists of allocating new places to workstations, following a spaghetti diagram. Goodbye to knots! And it also optimizes the distance that products, and logisticians, have to travel.

SIM (Short Interval Management)

System of ritualized meetings or team points (every day, every week, …). It is based on feedback from the field of performance indicators (S, Q, D, P) and problems. The more important the problem, the more it will go up in the hierarchical levels by a system of animation loops.


The SIPOC diagram – Supplier, Input, Process, Output, Customer – allows you to map out an entire process, from Supplier all the way to Customer.


Specific, Measurable, Achievable or Acceptable, Realistic and Timely

SMED Method

The SMED method consists in reducing the changeover times of production series on one step of a process (a machine most of the time) and aims to reduce this time to a minimum. The shorter this time is, the closer you will be to customer batch demand and thus achieve small production batches (for a better equipment flexibility)

Spaghetti diagram

Thanks to the Spaghetti Diagram you can see at a glance if the workstations are correctly located in your company … Make sure that the logisticians do not cross and do not have to travel miles to get the products to their destination !

Statistical Process Control

SPC allows to check if the process is stable.


Process mapping adapted to the services. Its name comes from its resemblance to the swimming lanes of a pool.

Task Management Board

The Task Management Board is a Kanban-type table that allows you to view the tasks of an office flow and reassign them, if necessary.

Transported batch

The transported batch is the quantity of product that the logisticians transport from one post to another.

Takt Rate

See Takt Time – Takt Rate is caculated by divided the average customer demand by the company opening time – (Unit : product / time)

Takt Time

The Takt Time (TT) is the ideal rhythm of your flow. How many folders, Production Orders (PO), requests … you have to deal with, during a period of time. To calculate the TT of your production, divide the company opening time by the average demand during this period (Unit : time / product)

Time required

The time required includes downtime such as breakdowns and unplanned staff absence, as well as scheduled downtime such as production changes, adjustments, etc. The time during which the machine(s) is actually producing is referred to as Running Time (Rt).

Tighten its flows

Tighten its flows is one of the 5 key principles of Lean. This consists of having only the necessary work-in-process and inventory in its process.

Total Productive Maintenance (TPM)

The TPM method (Total Productive Maintenance) aims to maximize the availability of production equipment (zero breakdown) while reducing investments. Usually, autonomous-maintenance is one of the first pillars to start.

“Underload” area

The “underload” area is the area of the Queue tool in which the company is over capacity.

Useful time

Useful time is the time actually spent producing without the time spent at NVA.


The voice of the customer is a process of listening to the customer’s expectations.


The VSM, or Value Stream Mapping, traces the flow of the product from the raw material (and even from the supplier) to the end customer by indicating the data necessary for each step. It allows you to better understand the problems of your business by condensing It often includes work in progress, time busy, cycle time, …

Work in-process

The work in-process is the number of products present on your production process. They are the sum of the “In” and “Out” of all of the company’s workstations. Each station also has its work in process, which therefore combines its In and Out. By decreasing or increasing it, your Lead time is impacted but watch out for other effects! (damaged products, waiting, …)


The workload corresponds to the occupation of a person or a team in work to achieve the objectives set.