The 5M Method and the Ishikawa Diagram: Essential Management Tools

What is the 5M Method?

The 5M method is a project management tool used to analyse the root causes of a problem. It is structured around the 5Ms, which represent the main families of possible causes for any given issue.

Historical note: The 5M method was created by Japanese professor Kaoru Ishikawa (1915–1989), which is why it is sometimes referred to as the “Ishikawa method”.

The five families (the 5Ms) are:

• Manpower: the organisation’s personnel, skills, motivation, headcount…

• Machinery: equipment, machines, software, and IT hardware…

• Materials: consumables, items processed in the production chain…

• Method: ways of working, procedures, instructions…

• Environment: working conditions, physical surroundings, interpersonal dynamics…

The 5M method is sometimes extended with additional categories, such as Measurement, which covers measurement methods, calibration, and the readability of results. When this family of causes is added, the 5M method becomes the 6M method.

It can also be extended with the following:

• Money, referring to sources of funding,

• Management, referring to hierarchical responsibilities and decision-making.

Building the Ishikawa Diagram

The Ishikawa diagram, also known as the cause-and-effect diagram or the 5M diagram, aims to identify and organise the causes of a problem into major families in a visual format. It is the visual tool of the 5M method. The process of constructing this diagram involves several steps:

• Brainstorm all potential causes of the problem as a team,

• Draw the Ishikawa diagram to graphically represent and classify the causes of a problem.

The Ishikawa diagram consists of a continuous line or arrow representing the problem. At the far left, the problem is stated as specifically as possible. Once the problem has been defined, five branches are drawn pointing towards the main line. These five branches are the 5Ms, which, as noted above, represent the main families of causes for a given problem.

Once the five branches have been drawn, the causes identified during the brainstorm are taken and distributed across the relevant families.

The final step is to draw up an action plan to reduce or eliminate the causes of the problem.

Ishikawa Diagram: a Production Delay Example

Let us take a first example of a problem in a factory: a production delay.

In our example, the factory is experiencing a production delay. The factory managers and operators carry out an analysis to identify the potential causes of this delay during a brainstorming session.

The production delay may be attributed to multiple factors, categorised within the main families (5M). The following causes are identified:

• Manpower: lack of motivation, insufficient staffing, and lack of training.

• Machinery: failure of electrical equipment, damage to certain machines.

• Materials: delays from the raw materials supplier, shortages.

• Method: lack of supervision.

• Environment: excessively demanding working conditions and a poorly organised environment.

Once these causes have been identified and prioritised, teams can find appropriate solutions to address the problem. They can then focus on the causes they consider most significant. In our case, they could, for example, apply the 5S methodology to improve working conditions and the organisation of the environment, and thereby restore motivation among operators.

Ishikawa Diagram: example of declining customer satisfaction in a clothes shop

Let us take another example: a decline in customer satisfaction in a clothes shop.

In the same way as for the previous example, an analysis is carried out to identify the potential causes of this dissatisfaction. It is attributed to supply problems, excessively long waiting times at the checkout, a gloomy environment, and a printer malfunction.

From this information, the causes can be categorised as follows:

• Machinery: insufficient number of checkout tills, delivery lorries frequently breaking down.

• Materials: paper waste (faulty printer).

• Method: lack of procedures.

• Environment: inadequate lighting.

Similarly, the goal is to find appropriate solutions to address the problem. In our example, it may be relevant for the shop to invest in lighting and checkout tills, in order to minimise the causes of the malfunction.

Why use the 5M method?

Thanks to the 5M method and its horizontal visualisation tool, defective phenomena are better understood. By identifying the root cause of the problem, this method not only creates an optimal environment within teams for finding effective solutions, but also helps anticipate other causes that could worsen the problem.