What is a fish bone diagram?

The Ishikawa scheme is a graphical tool for finding and visualizing the causes that led to the problem situation. The method is used in business. Initially, it was used in production, but now it is a diagram for any difficulties, including managerial and financial.

The tool is also called a causal scheme. Because the diagram is based on a consistent relationship between two or more factors.

When drawing up the diagram, the head asks the question: what led to such an outcome of events?Sometimes the result is negatively affected by several factors at the same time. The Ishikawa scheme provides for the opportunity to record and review them all. The theory does not represent the situation in the black and white spectrum, when the problem has one specific cause, but in all the variety of shades - factors that affect the situation from different sides. By the way, it is because of this that the diagram has a species of fish skeleton: together the ribs - a list of reasons that lead to the problem.

The diagram was named after its creator. The method was developed by Japanese scientist Kaoru Ishikawa, a member of the quality management research group. His activities were closely related to the philosophy of lean production of kaizen and the method of managing kanban projects.

The most famous inventions of Kaoru Ishikawa are quality circles and a causal diagram. Both methods were adopted by Toyota. Other enterprises followed her example over time.

The Ishikawa diagram is a diagram in the shape of a fish skeleton. Due to the similarity with fish, the method is called Fishkawa, or Fishbone Diagram.

Goals of the Ishikawa diagram

Kaoru Ishikawa, together with the Union of Japanese Scientists and Engineers in 1979, identified 7 basic quality control tools that allow you to quickly find problems in production and solve them:

1. Checklist.
2. Histogram.
3. Pareto diagram.
4. Control table.
5. Diagram of the scatter.
6. Stratification.
7. Causal diagram "fish bone".

They are still used, because the clarity of the analysis methods allows them to be carried out even without education in the field of statistics and quality control. The main task of using the method is to improve the quality of business processes.

Kaoru Ishikawa believes that changes to production should be introduced gradually. First you need to implement an improvement in one department, check the results. If they are positive, save and distribute the changes, making them the quality standard.

But in order to introduce an improvement into production, you need to find a problem area that needs to be fixed. A fishkawa will be useful for this.

Ishikawa diagram what business needs for:

• to analyze the problem and identify the main cause;
• to find methods to solve a negative situation and eliminate its consequences;
• to prevent similar mistakes in the future;
• to choose a way to improve business processes.

In the Ishikawa scheme, the problem is not isolated from the surrounding business processes. On the contrary, the manager gets the opportunity to look at the situation in a comprehensive way. He sees the connection between different factors, for which the Ishikawa diagram takes into account the departments, activities of the company. Different bones are superimposed on the fish - employees, processes, materials, external conditions. It turns out a schematic skeleton of business.

The Ishikawa diagram is used to improve current business processes, develop new products and identify negative factors.

Advantages of the Ishikawa chart - quality management and improvements

Why did the fish skeleton scheme become popular among managers? Advantages of the method:

1. Ease of compilation. The diagram consists of understandable elements. All the "bones" of the skeleton are easy to find - in the financial statements of the business, sales indicators and so on. The manager can draw up a scheme with minimal preliminary preparation. For example, net profit decreased due to the reduction of regular customers. To confirm this and highlight it in a separate "bone", the manager goes to CRM and segments customers by the number of purchases. He sees that the number of regular customers has decreased compared to the previous year, so he put this factor on the scheme.
2. Clear visualization. The Ishikawa model immediately shows the main and secondary factors. The scheme is easy to read.
3. Convenience of team composition. You can draw a fish skeleton by hand on the board during a meeting. When the manager starts looking for factors that affect the problem, employees join and help fill the skeleton. This is a good starting point for further discussion - you can hold a meeting based on the scheme.
4. Reuse. If there is a problem with similar roots later, you can take an old fish skeleton as the basis of the diagram. It will have bones that remain unchanged for the company. The scheme can be modified - remove or add details.
5. Universality. The Ishikawa method is a quality control tool in different industries and departments: in sales, services, in production.
6. Systematization of factors. All causes are organically grouped by directions - fish ribs.
7. The result and the process of building the fish skeleton of the diagram are important. During the discussion, important topics are raised, solutions are found. Sometimes it is useful to "make the problem some by bones" so that employees get deeper into the company's workflows. This contributes to the cohesion of the team.

What elements does the Ishikawa diagram include?

The causal relationship diagram is a tree diagram. Several branched lines - branches - depart from the straight line, that is, the trunk. Therefore, the diagram is called the Ishikawa tree. But if you traditionally arrange the scheme horizontally, it looks more like a fish.

The diagram consists of 3 parts:

• fish head;
• spine;
• bones.

Fish head

The head is a problem. It can be a situation that has already occurred or a hypothetically possible incident. We need to formulate the problem and write it into your head. Visually, it can be any geometric figure, traditionally - a triangle.

Fish spine

The spine, that is, the ribs of the fish, are the main factors that can affect the problem. The main axes of the Ishikawa diagram can be collected in categories. For example, the "employees" edge includes everything related to personnel - number, ability to work, motivation. There are no strict requirements for the number and location of ribs. But there is a recommendation - the stronger the factor affects the problem, the closer it is to the head. It is worth leaving less significant categories of reasons in the tail. It helps to focus attention on the most important thing.

Fish bones

Smaller bones depart from the ribs of fish - secondary factors that can affect the situation. There may be several reasons in one category. For example, bones can depart from the edge of "employees": "insufficient qualifications", "regular delays", "staff turnover". Together, they give one common cause of the problem. You can consider bones in a complex or separately.

What does the Ishikawa diagram show: how to build a fish

Working with the fish bone scheme includes 5 stages:

1. Identifying the problem.
2. Search for common reasons.
3. Details of the reasons.
4. Analysis of the diagram.
5. Finding a solution.

Let's look at an example of how to make an Ishikawa diagram.

Formulation of the problem

When processes occur in a company that jeopardize the results of the organization's work, the first thing they need to be identified and clearly formulated. The problem may be:

• Completed. Example: sales decreased by 20% over the year. The manager is looking for a solution.
• Hypothetical. Example: when launching a new product, there is a risk that it will not exceed the payback threshold for 3 months of sales. The manager is looking for a way to prevent a negative situation.

A clearly formulated problem should be written in the head of the fish.

We need to assemble a group that will discuss the situation, its causes and solutions. The team should include people from different departments, including those employed in production.

Andrey's company is engaged in roofing works. The entrepreneur drew attention to the fact that over the past six months, the team began to regularly hand over objects with a delay. Because of this, negative customer reviews appear, and the company manages to fulfill fewer orders - profits fall. Andrei decided to use the Ishikawa diagram method to find a solution. To do this, he created a group consisting of himself, a foreman and one roofer, and also formulated the problem: 80% of orders were completed in violation of deadlines.

Search for common reasons

When building an Ishikawa diagram, 3 to 6 main factors are usually distinguished. You can choose them yourself or use standard categories, depending on the problem:

• employees;
• transport and equipment;
• materials for production;
• methods and technologies;
• measurements, that is, errors in calculations;
• environment;
• product or service;
• cost price;
• marketing;
• trading platform;
• suppliers.

Why does Andrei's roofing company regularly violate the deadlines for the delivery of objects? Together with the foreman and the roofer, the entrepreneur identified 5 main categories. And I drew ribs for the fish:

Details of the reasons

When the spine is schematically drawn, you can supplement the diagram with fish bones by brainstorming. The group members discuss the potential causes of the problems and throw ideas. Even if the factor seems insignificant, it also needs to be added to the scheme. Because sometimes the problem consists of several small reasons.

The main rule by which factors are added to the scheme: the presence of a causal relationship.

The discussion group, headed by Andrei, began to generate ideas. The manager entered them into the scheme. It turned out this schedule of Ishikawa:

It turned out that violations of deadlines began along with several changes:

1. To make the roof cheaper, the team decided to make gutters, end strips and ribs on their own, and not to buy ready-made ones. Cutting and bending metal sheet takes time.
2. To extend the service life of the roof, not pine, but larch was used for crates - heavy wood requires more time and effort for lifting and installation.

In addition, the group members identified constant problems that relate to management and employees. For example, there is no motivation system, which is why workers are often late, go on sick leave and generally do not seek to work more efficiently.

Minor problems were also found. For example, due to the breakdown of electrical equipment, roofers have to use mechanical machines.

Analysis of the diagram

When the fish skeleton is compiled according to the Ishikawa method, it is necessary to determine which factors can be changed and which cannot. Those that cannot be influenced can be crossed out. The most important ones are to highlight to focus attention on them. If several reasons can be eliminated by one solution, they should be combined for convenience.

If the Ishikawa fish diagram turned out to be branched, it is difficult to highlight 2-3 main causes of the problem. Then it is worth dividing the factors according to the degree of priority into several groups.

Andrei crossed out the factors that he decided not to influence. He removed everything related to materials, as he considered the increase in quality and cost reduction more significant than reducing the terms.

The entrepreneur outlined the reasons that need to be dealt with first - repair of equipment and introduction of control over the timing of work at the foreman level. The head combined two factors that concern employees, as they are solved by one action. The rest of the reasons are less significant. It turned out a causal diagram - an example:

Finding a solution

When the causes that led to the problem are identified, it is necessary to develop a strategy for their elimination.

The search for solutions is carried out by the group. Participants offer different options for correcting the situation. Then they set priorities. Implement decisions in order:

1. Cheap and fast. For example, to repair an electric folding machine. Repair will take 1-2 days. Then the workers will use electric, not hand tools. They will be able to perform the task of closing the fold twice as fast.
2. Cheap, but long-lasting. In our example, this category of solutions includes the introduction of standards according to which the foreman will keep track of the working hours of roofers. The manager decided to use the Kanban board. It is convenient to divide projects into tasks and make separate cards for them. So you can control each stage of roofing work and track when there are delays in deadlines.
3. Fast, but expensive. Training roofers and advanced training of beginners requires material and time costs. But this will give an excellent long-term result - the team will work faster, more harmoniously and better. In addition, it will be easier to close the problem with frequent hospital roofers. At this time, he will be replaced by new trained workers.
4. Expensive and long. The head Andrey attributed two solutions to this category. First, the purchase of an electric sheet bender. It's expensive, and now the company has no free funds to buy. Secondly, building a motivation system for employees. This would help to solve the issue of being late. In Ishikawa's diagram, an example of expensive and long-term solutions are factors that are not outlined, but also not crossed out.

As a result of using the Ishikawa diagram, the fish skeleton, the entrepreneur found the reasons why 80% of orders were completed in violation of deadlines, identified the main ones and developed a plan to eliminate negative factors.

When is it convenient to use the Ishikawa diagram, and when it is not

The Ishikawa diagram is used to find the best methods for solving problems. It is suitable for the production cycle, as it was created for it. But over time, Ishikawa's fish bone began to be used everywhere - in trade, marketing, management, finance. Therefore, there are no restrictions on the use of the method from the point of view of the industry.

But there are situations when Kaoru Ishikawa's diagram is not useful or will be too complicated. Let's look at the table:

The Ishikawa diagram is a tool for finding and visualizing the factors that led to the problem. With a scheme that looks like a fish bone, you can quickly find the company's weaknesses and the best method of solving problems.