Diagrama de Ishikawa🐠 : Causa y Efecto- Tipos-Ejemplo
Introduction to Ishikawa Diagram
Overview of the Ishikawa Diagram
- The Ishikawa diagram, also known as the cause-and-effect diagram, illustrates the systematic relationship between a fixed outcome and its causes.
- It serves as an analytical tool for problem-solving, helping teams classify and relate various factors affecting a process.
- Developed by Professor Kaoru Ishikawa in 1943, it was initially used to improve quality control in a Kawasaki plant.
Purpose and Benefits
- The diagram promotes knowledge exchange among team members, enhancing their understanding of problems and potential solutions.
- It aids in identifying data types needed for analysis and confirming if related factors are indeed causing issues.
- By providing an overview of contributing factors or phases in a process, it helps prevent future problems through appropriate controls.
Understanding Cause and Effect Relationships
Defining Effects
- The "effect" represents areas needing improvement—problems to solve or quality characteristics to enhance. Once defined, contributing factors can be identified.
Examples of Cause and Effect
- Incorrectly filled order forms lead to non-delivery of goods to customers.
- Variations in procedures result in differing processing times for credit requests.
- Lack of employee training correlates with increased customer complaints received.
How to Construct an Ishikawa Diagram
Steps for Creation
- Clearly define the effect or symptoms that need investigation; position this on the right side with a central line pointing leftward.
- Utilize brainstorming techniques to identify possible causes; connect these causes with lines inclined at about 70 degrees from the central line.
Standard Classifications of Causes
- 4M Classification: Focuses on Man (personnel), Machine (technology), Method (procedures), Material (raw materials), and Environment (surroundings). This is commonly used when production issues arise.
- Quality Issues: A second classification emphasizes resources like communication, training, and management practices relevant to quality concerns.
- Administrative Topics: A third classification addresses administrative causes such as policies, procedures, facilities, and personnel management strategies relevant for organizational effectiveness.
Identifying Main Causes
Brainstorming Process
- Teams should compile lists of all potential causes during brainstorming sessions.
Analysis of Root Causes in Problem Solving
Understanding the Depth of Analysis
- The goal is to delve deeply into the root cause of a problem, ensuring clarity and thoroughness in understanding both causes and effects. This involves logical verification of the entire analysis chain.
- It is essential to verify the integrity of the diagram structure, including its branches and sub-causes, making it as accurate as possible relative to the reality being analyzed.
Types of Diagrams for Analysis
- There are three main types of diagrams used in this context:
- Variability analysis diagrams (commonly known as quality characteristic dispersion diagrams).
- Stage process analysis.
- Process par analysis.
Variability Analysis Diagram
- The first step involves drawing a thick line from left to right, labeling the effect being analyzed (e.g., customer dissatisfaction). Key causal factors are then identified and linked with arrows to this main effect.
- Four primary causes identified include:
- Products sold.
- Labor issues.
- Procedures.
- Transportation challenges. Each can be further subdivided into smaller branches or "spines."
Sub-Causes Identification
- For example, under "products sold," issues may arise from lack of standard procedures or incomplete processes during delivery. In transportation, problems could stem from route scheduling difficulties or vehicle maintenance issues. Labor concerns might involve employee attitude or insufficient training.
- Each cause and sub-cause can be examined more closely by asking fundamental questions: who, what, where, when, and why? This approach aims to reach the core issue effectively.
Stage Process Analysis
- The second type discussed is stage process analysis which helps identify problems arising from a series of events within a process where it's unclear which event caused an issue. Each category is scrutinized for potential causes after identifying significant ones through this method.
- This type facilitates communication between operations teams and can help prevent future problems by addressing quality concerns at each phase of production or service delivery.
Combined Process Diagram
- The final type combines cause-and-effect diagrams with models (like drawings or photographs) that illustrate various causes impacting different parts of a product or service (e.g., engine malfunction in a car). This comprehensive view allows for better decision-making when multiple issues exist simultaneously within one product/service context.