Baseline assumptions

Lines of COBOL

800B

Developers available (global)

100K

AI productivity multiplier

5×

Traditional SDLC — Input

Lines per dev per day

150

Traditional SDLC — Total elapsed calendar time (with AI)

844 years

Without AI:

1,212 years

Traditional SDLC

  • Discovery & archaeology: 13.5 yrs
    • Dependency mapping, business logic extraction, documentation
  • Requirements & BA analysis: 101.3 yrs
    • BA workshops, business rule capture, stakeholder sign-off
  • Architecture & design: 67.5 yrs
    • Target Java architecture, data model, API design, cloud infra
  • Code migration (AI-assisted): 33.8 yrs
    • COBOL → Java translation, refactoring, code review
  • Unit & integration testing: 127.0 yrs
    • Automated test generation, CI/CD pipeline, coverage validation
  • Functional testing: 84.4 yrs
    • End-to-end functional validation against COBOL behavior
  • Parallel / shadow running: 84.4 yrs
    • Dual-run old + new, output reconciliation, discrepancy resolution
  • BA / UAT / business testing: 67.5 yrs
    • Business acceptance, edge case validation, sign-off cycles
  • Regulatory & compliance: 33.8 yrs
    • Audit trails, SOX/PCI/Basel compliance validation, regulator approval
  • Deployment & cutover: 25.3 yrs
    • Phased rollout, fallback planning, prod monitoring
  • Post-migration stabilization: 16.9 yrs
    • Hypercare, incident response, performance tuning

Scenarios

  • Conservative: 1,964 years
  • Pessimistic: 800B lines · 150 lpd · 50K devs · 2× AI
  • Base case: 844 years
  • Most likely: 800B lines · 150 lpd · 100K devs · 5× AI
  • Optimistic: 391 years
  • Best-case: 800B lines · 150 lpd · 200K devs · 15× AI

MO Process — Input

Lines per dev per day

1,200

MO Process — Total elapsed calendar time (with AI)

47 years

MO Process

  • Analyze source code: 2.7 yrs
  • Capture production data: 22.8 yrs
  • Generate a modern replica candidate: 18.3 yrs
  • Verify behavioural equivalence: 16.4 yrs
  • Verify performance and integration equivalence: 9.1 yrs
  • Regulatory & compliance: 3.7 yrs
  • Integrate into production: 9.1 yrs
  • Project management overhead: 9.1 yrs

Scenarios

  • Conservative: 127 years
  • Pessimistic: 800B lines · 1,200 lpd · 50K devs · 2× AI
  • Base case: 47 years
  • Most likely: 800B lines · 1,200 lpd · 100K devs · 5× AI
  • Optimistic: 20 years
  • Best-case: 800B lines · 1,200 lpd · 200K devs · 15× AI

Traditional SDLC model inspired by Vikas Pujar's LinkedIn post

MO Process by Mechanical Orchard

800B LOC estimate from Rocket Software survey