oci-deal-accelerator/docs/design-phase.md

DESIGN Phase — Detailed Guide

The DESIGN phase produces a complete, defensible architecture. Output: agreed architecture, cost estimate, operations model, and solution proposal.

Steps

1. Current State (People, Process, Technology)

Capture enough about the current state to architect the future. Frame the problem — don't gather exhaustive requirements.

Artefacts:

• Discovery Questionnaire (templates/discovery-questionnaire.yaml) — structured customer data collection
• Business & Security Constraints — time, funding, legal, compliance, technology constraints
• Current State Apps & Tech Portfolio — systems, assets, integrations
• Prioritization Matrix — score apps by criticality, fit, potential, risk (in discovery questionnaire)
• Current State Architecture — diagrams of current environment

Technology (existing in Workload Profile):

• Databases, compute, middleware, messaging, storage, networking, identity, integration
• Use config/workload-profile-schema.yaml for field definitions

People (new — added to Workload Profile):

• Team size and roles (DBAs, cloud engineers, DevOps, security)
• Skill gaps relevant to the proposed solution
• Managed services preference (self-managed → fully managed)
• Change management readiness (how resistant is the org to change?)

Process (new — added to Workload Profile):

• Deployment process (manual, CI/CD, IaC maturity)
• Change management process (CAB, lightweight, none)
• Incident response process (NOC, on-call rotation, outsourced)
• Backup/recovery testing frequency

Guidelines:

• Frame the problem — don't gather exhaustive requirements
• Be collaborative — share everything with the customer
• Use whatever works — top-down and bottom-up
• Understand business context, drivers, and desired outcomes
• Be very clear about scope — which systems are in and out

ECAL Artefacts: See kb/patterns/ecal-artefacts-catalog.yaml DES-01 through DES-09 Engagement RACI: See kb/patterns/engagement-raci.yaml design.current

2. Future State (Solution Design)

Given the Workload Profile and Current State, compose a complete architecture. This step produces multiple design artifacts:

Solution Design

Core architecture composition — the existing Phase 2 workflow:

1. Select services from kb/services/
2. Dimension using kb/sizing/ rules
3. Compose topology from kb/patterns/ blocks
4. Estimate costs with explicit assumptions
5. Validate against Well-Architected Framework (kb/well-architected/)

Deployment Design

How the solution gets built and deployed:

• Environment strategy (dev, test, staging, prod)
• IaC approach (Terraform, Resource Manager, Ansible)
• CI/CD pipeline design
• Non-production environment sizing (typically 50% of prod for test, 25% for dev)

Transition Design

How to get from current state to future state:

• Migration strategy per component (lift-and-shift, re-platform, re-architect)
• Migration tooling (DMS, GoldenGate, RMAN, Data Pump, ZDM)
• Phased migration plan with dependencies
• Parallel run requirements and cutover strategy
• Rollback plan for each phase

Operations Model

How the solution will be operated day-to-day:

• Use templates/operations-model.yaml as the artifact template
• Monitoring and alerting strategy (OCI Monitoring, Logging Analytics, 3rd party)
• Patching and maintenance windows
• Backup and recovery procedures
• Incident response and escalation
• Capacity management and scaling triggers

Guidelines:

• Always look for a quick win the customer can see early
• The operational model is just as important as the architecture
• Don't forget non-production environments
• Security and data locality must be understood early

3. Confirm (Solution Proposal)

Assemble all design work into a solution proposal for stakeholder decision.

Activities:

• Assemble the slide deck with all architecture artifacts
• Prepare the business case: costs, benefits, timeline, risks
• Ensure all propositions are SMART:
  • Specific: "Migrate 3 Oracle databases to ADB-S" not "Move to cloud"
  • Measurable: "Reduce DB admin effort by 60%" not "Improve efficiency"
  • Attainable: Validated against feature matrix and field findings
  • Relevant: Tied to the business driver from the Value Story
  • Time-based: "8-week migration" not "as soon as possible"
• Include competitive positioning if relevant (kb/competitive/)

Output artifacts by tier:

Artifact	Small	Standard	Complex
Slide deck (.pptx)	6-8 slides	10-12 slides	12-15 slides
Architecture diagram	Single-page	Single-page	Multi-page
Cost estimate	In-deck table	Separate .xlsx	Detailed .xlsx
ADRs	2-3 inline	4-6 in appendix	Full ADR docs
Migration plan	1 slide	2-3 slides	Separate doc
Operations model	In-deck summary	1-page summary	Full template
Risk register	Top 3-5	Top 5-8	Full register
WA scorecard	Traffic lights	With recommendations	Full report

Guidelines:

• Don't say anything you cannot back up with evidence
• The roadmap must be achievable
• Think about the person you are presenting to — what does it mean for them
• Quality of the presentation matters — it must look professional

Iterative Checkpoint

Before moving to DELIVER (or presenting to customer):

- [ ] Architecture validated against WA Framework (no critical gaps)
- [ ] Cost estimate reviewed with explicit assumptions
- [ ] Migration plan is achievable within stated timeline
- [ ] Operations model addresses day-2 concerns
- [ ] All propositions are SMART
- [ ] Risk register has mitigations for all HIGH items
- [ ] Feature compatibility checked (no blockers)
- [ ] Field findings reviewed (no known issues unaddressed)