The Ship of Theseus: Program Strategy
Live Modernization of Critical Enterprise Services (ES)
Executive Summary
Project Title: The Ship of Theseus: Live Modernization of Critical Enterprise Services (ES)
The challenge is to transform the 13-15 year old, mission-critical ES monolith into a modular, future-proof platform compliant with TM Forum Open Digital Architecture (ODA), without interrupting continuous, high-volume operations (billing, provisioning, revenue management).
Our strategy is a "Rolling Replacement" using the Strangler Fig Pattern. We will replace components incrementally, ensuring zero downtime and continuous business evolution. This approach minimizes risk while establishing a globally recognized ODA standard and positioning the client as a digital innovator through API certification and TM Forum engagement.
The program is structured around three core pillars designed to maximize technical delivery while securing long-term business advantage.
| Pillar | Description | Business Value Proposition |
|---|---|---|
| The ODA Blueprint | Mapping existing ES capabilities to the TM Forum ODA framework to define the new microservices architecture. | Future-Proofing: Establishes a globally recognized, modular standard, enabling faster integration and vendor neutrality. |
| Live, Phased Replacement | Using the Strangler Fig Pattern to replace monolith components incrementally with new ODA-compliant microservices. | Zero Downtime: Guarantees business continuity and minimizes operational risk. |
| API Certification & Leadership | Certifying new Open APIs and participating in TM Forum events (e.g., Catalyst Projects) to showcase the modernization success. | Competitive Advantage: Certifications validate system quality; Thought leadership positions the client as a digital innovator. |
The "Rolling Replacement" is executed via a four-step cycle for each legacy component ("plank"):
- Define the ODA Target: Map the legacy component to the exact TM Forum ODA and Open API standards.
- The Strangler Fig: Introduce an API Gateway to intercept traffic. This gateway redirects requests for new capabilities to the new microservice while keeping the monolith for everything else.
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Phased Rollout:
- Phase 1 (Read): New microservice handles data lookups.
- Phase 2 (Write): New microservice handles data updates, synchronizing with the old system until stabilized.
- Decommissioning: Once stable, the new service becomes the sole system of record, and the corresponding legacy code in the monolith is formally retired. The key metric is the Monolith Code Retirement Rate.
The program is also designed to maximize market visibility and drive industry recognition for the successful delivery model:
- Narrative Framing: Constant use of the "Ship of Theseus" metaphor to communicate progress and manage complexity internally and externally.
- TM Forum Catalyst: Submission of a TM Forum Catalyst Project titled: "The Live Replacement: Rebuilding a Telco Ship While It Was Still Sailing."
- Joint Case Study: Development of a high-profile, joint case study focusing on the risk-mitigation and ODA certification achievements.
- API Certification: Prioritizing and achieving TM Forum Open API Certification for initial critical services (e.g., Party Management) to validate quality.
Next Steps
We recommend immediately initiating the ODA Blueprint Mapping Workshop with key architects and business stakeholders to formalize the replacement roadmap and select the first component for live migration.