flowchart LR
    A["Only accounting costs<br/>are considered<br/>Focus on explicit spend,<br/>implicit losses ignored"] --"Apply the opportunity<br/>cost concept"--> B["Explicit cost +<br/>implicit opportunity cost<br/>= true economic cost"] --"Compare alternatives,<br/>choose the optimum"--> C["Optimized resource<br/>allocation decision"]

    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 R1["　"]
        direction LR
        T1["Explicit cost<br/>Explicit Cost<br/>Actual accounting<br/>expenditure<br/>Server purchase, labor, licensing"]
        T2["Implicit opportunity cost<br/>Implicit Opportunity Cost<br/>The value of the alternative<br/>forgone by the choice<br/>Savings had you bought instead of built"]
    end
    subgraph R2["　"]
        direction LR
        T3["Sunk cost<br/>Already incurred<br/>and unrecoverable<br/>Must be excluded from the decision"]
        T4["True economic cost<br/>Economic True Cost<br/>Sum of explicit cost<br/>and opportunity cost<br/>The real cost of the decision"]
    end

    style T1 fill:#E3F2FD,stroke:#1976D2,color:#000
    style T2 fill:#F3E5F5,stroke:#7B1FA2,color:#000
    style T3 fill:#FFEBEE,stroke:#D32F2F,color:#000
    style T4 fill:#E8F5E9,stroke:#388E3C,color:#000
    style R1 fill:none,stroke:none
    style R2 fill:none,stroke:none
  

    flowchart LR
    OPT["Investment decision<br/>list of alternatives"]

    subgraph ALT["Value analysis per alternative"]
        direction TB
        A1["Alternative A: build in-house<br/>Cost: KRW 500M<br/>Expected benefit: KRW 1B<br/>Net value: KRW 500M"]
        A2["Alternative B: adopt SaaS<br/>Cost: KRW 200M<br/>Expected benefit: KRW 700M<br/>Net value: KRW 500M"]
        A3["Alternative C: open source<br/>Cost: KRW 100M<br/>Expected benefit: KRW 500M<br/>Net value: KRW 400M"]
    end

    SEL["Chosen: Alternative A"]
    OPC["Opportunity cost = net value of the best<br/>forgone alternative B = KRW 500M"]

    OPT --> ALT
    ALT --> SEL
    SEL --> OPC

    style SEL fill:#1E3A5F,stroke:#1E3A5F,color:#fff
    style OPC fill:#FFEBEE,stroke:#D32F2F,color:#000