Case Study 1: GlobalBank Five-Year Modernization Roadmap

The Context

GlobalBank's board asked a simple question: "Should we replace our COBOL systems?" Priya Kapoor's answer was a 30-page analysis comparing three options.

The Three Options

Option A: Full Replacement

  • Convert all 1.2 million lines of COBOL to Java
  • Migrate from z/OS to cloud-native architecture
  • Estimated cost: $850 million over 10 years
  • Risk: 40-60% failure rate based on industry data
  • Key concern: Business rule migration accuracy

Option B: Status Quo

  • Continue maintaining COBOL as-is
  • No new tooling or processes
  • Estimated cost: $8 million/year (current run rate)
  • Risk: Talent gap as senior developers retire; no integration with modern channels
  • Key concern: Inability to serve mobile and digital customers

Option C: Modernization (Selected)

  • Keep COBOL core, modernize everything around it
  • CI/CD, APIs, hybrid architecture, AI tools, talent development
  • Estimated cost: $4.2 million over 5 years
  • Risk: Medium (incremental approach reduces risk)
  • Key concern: Requires sustained organizational commitment

The Decision

The board chose Option C based on three factors: 1. Economics: $4.2M vs $850M — a 200:1 cost ratio 2. Risk: Incremental modernization has no single point of failure 3. Speed: Year 1 deliverables were already partially complete (CI/CD, initial APIs)

Year-by-Year Plan

Year 1 (Foundation): Git migration, CI/CD pipeline, z/OS Connect, knowledge transfer program. Budget: $800K.

Year 2 (Integration): 20 COBOL APIs exposed, event streaming, ADDI deployment, apprenticeship program. Budget: $900K.

Year 3 (Analytics): Cloud data warehouse via CDC, analytics dashboards, AI documentation project, 3 new junior hires. Budget: $950K.

Year 4 (Optimization): Refactor 50 high-complexity programs, 80% test coverage, selective cloud batch migration. Budget: $850K.

Year 5 (Maturity): Full hybrid architecture, API catalog of 100+ services, team at 8 developers, continuous modernization process. Budget: $700K.

Projected Outcomes

Metric Before After (Year 5)
Deployment frequency 2/month 12+/month
API endpoints 0 100+
Test coverage ~5% 80%
Mobile/web integration Screen scraping Native REST APIs
Mean time to recover 4 hours 30 minutes
Developer team size 5 8
Average developer age 46 38

Discussion Questions

  1. What assumptions must hold true for Option C to succeed? What could go wrong?
  2. If the talent gap worsens (no new hires available), how would you modify the plan?
  3. The board approved the plan in 22 minutes. What does this suggest about the quality of the presentation?
  4. At what point, if ever, should GlobalBank reconsider Option A (full replacement)?