Legacy Modernization - sgml/signature GitHub Wiki

Front End

Hardware

Waterfall

+------------------------------------+
| Requirements Gathering             |
| • Capacity targets                 |
| • Performance SLAs                 |
+------------------------------------+
               |
               v
+------------------------------------+
| System Design                      |
| • Mainframe-to-CPU mapping         |
| • Network & storage topology       |
+------------------------------------+
               |
               v
+------------------------------------+
| Hardware Procurement & Assembly    |
| • Order microprocessor nodes       |
| • Rack build-out                    |
+------------------------------------+
               |
               v
+------------------------------------+
| Integration & Testing              |
| • Hardware-in-the-loop emulation   |
| • Firmware & driver validation     |
+------------------------------------+
               |
               v
+------------------------------------+
| Deployment & Commissioning         |
| • Cutover batch jobs               |
| • Migrate live workloads           |
+------------------------------------+

Agile Scrum

     +------------------------------------------------+
     |                Product Backlog                 |
     | - Virtualize key batch workloads               |
     | - Containerize legacy data services            |
     | - Develop FPGA-accelerated node prototype      |
     +------------------------------------------------+
                         |
                         v
                    +---------+
                    | Sprint  |
                    | Planning|
                    +----+----+
                         |
                         v
   +------------------------------------------------+
   |             Iteration Cycle (2–4w)             |
   | 1. Design & Procure small hardware slice       |
   | 2. Integrate & Test in CI pipeline             |
   | 3. Demo to stakeholders, collect metrics       |
   | 4. Refine requirements based on feedback       |
   +------------------------------------------------+
                         |
                         v
              [Incremental Rollout to Prod]
                         |
                         v
   +------------------------------------------------+
   |           Definition of Done (DoD)             |
   | • All CI tests green                           |
   | • Performance SLAs validated in staging        |
   | • Stakeholder acceptance demo completed        |
   | • Documentation & runbooks updated             |
   +------------------------------------------------+

AgileFall

+-----------------------------+       +-----------------------------+
| Upfront Requirements &      | ----> | High-Level Design &         |
| Architecture Definition     |       | Strategic Procurement       |
+-----------------------------+       +-----------------------------+
                                              |
                                              v
                                     +----------------------------+
                                     |      Scrum Sprints         |
                                     | +------------------------+ |
                                     | | Sprint 1: Virtualize   | |
                                     | | Sprint 2: Containerize | |
                                     | | Sprint 3: FPGA Module  | |
                                     | +------------------------+ |
                                     +----------------------------+
                                              |
                                              v
                                     +-----------------------------+
                                     | Final Integration &         |
                                     | Production Cutover          |
                                     +-----------------------------+
                                              |
                                              v
                                     +-----------------------------+
                                     |       Definition of Done    |
                                     | • All sprints accepted      |
                                     | • End-to-end tests passed   |
                                     | • Rollback & monitoring plan|
                                     | • Support handover & docs   |
                                     +-----------------------------+