flowchart LR
    A["Collecting arbitrary metrics<br/>with an unclear measurement purpose<br/>makes the data unusable"] --"Design in reverse:<br/>Goal → Question → Metric"--> B["A goal-aligned,<br/>meaningful metric system"] --"Data-driven<br/>quality decisions"--> C["Continuous quality improvement<br/>based on measurement"]

    style A fill:#FFEBEE,stroke:#D32F2F,color:#000
    style B fill:#E3F2FD,stroke:#1976D2,color:#000
    style C fill:#E8F5E9,stroke:#388E3C,color:#000
  

    flowchart TD
    subgraph GOAL["Goal Layer"]
        G["Goal<br/>Defines the measurement object, purpose,<br/>viewpoint, and environment along 4 dimensions<br/>e.g., Evaluate the development process<br/>in order to reduce defects"]
    end

    subgraph QUES["Question Layer"]
        direction LR
        Q1["Question 1<br/>What is the<br/>current defect rate?"]
        Q2["Question 2<br/>When are<br/>defects found?"]
        Q3["Question 3<br/>What are the main<br/>causes of defects?"]
    end

    subgraph MET["Metric Layer"]
        direction LR
        M1["Metric 1<br/>Defects per unit of function<br/>Defect Density"]
        M2["Metric 2<br/>Defect detection rate by phase<br/>Phase Containment"]
        M3["Metric 3<br/>Distribution of defect causes<br/>Defect Causal Analysis"]
    end

    GOAL --> QUES
    Q1 --> M1
    Q2 --> M2
    Q3 --> M3

    style GOAL fill:#1E3A5F,stroke:#1E3A5F,color:#fff
    style QUES fill:#E3F2FD,stroke:#1976D2,color:#1E3A5F
    style MET  fill:#E8F5E9,stroke:#388E3C,color:#1B5E20
  

    flowchart LR
    S1["1. Define goal<br/>Write the 4-dimension Goal<br/>reach stakeholder agreement<br/>fix measurement scope"]
    S2["2. Derive questions<br/>List questions that<br/>confirm goal achievement<br/>review measurability"]
    S3["3. Design metrics<br/>Define quantitative/qualitative<br/>metrics that answer each question<br/>decide methods & tools"]
    S4["4. Collect data<br/>Establish measurement plan<br/>automated/manual collection<br/>verify data quality"]
    S5["5. Interpret & feed back<br/>Interpret backward toward the Goal<br/>judge goal achievement<br/>establish corrective action"]

    S1 --> S2 --> S3 --> S4 --> S5
    S5 -->|"Revisit the goal"| S1

    style S1 fill:#1E3A5F,stroke:#1E3A5F,color:#fff
    style S2 fill:#E3F2FD,stroke:#1976D2,color:#000
    style S3 fill:#F3E5F5,stroke:#7B1FA2,color:#000
    style S4 fill:#FFF3E0,stroke:#F57C00,color:#000
    style S5 fill:#E8F5E9,stroke:#388E3C,color:#000