Appraise Phase - >6 yrs to 3 yrs before CoP

Assess Phase - >6 yrs to 3 yrs before CoP

Define Phase - >3 yrs before CoP

Execute Phase - Post-CoP

  • Strategy alignment (corporate and NSTA) - Appraise Phase to Post-CoP
  • Cost forecasting & performance benchmarking - Appraise Phase to Post-CoP
  • Learning and knowledge review (inc. technology assessment) - Appraise Phase to Define Phase
  • Evaluate asset condition - Appraise Phase to Assess Phase
    Infrastructure reuse/repurposing assessment - Appraise Phase to Assess Phase
  • Contracting/execution strategies - Assess Phase to Define Phase
    Tendering - Define Phase
  • Concept development - Appraise Phase
  • Develop decom plans - Assess Phase
  • Detailed engineering - Define Phase
  • Scope aggregation opportunities - Assess Phase to Define Phase
  • Implement repurposing/decom prep - Assess Phase to Post-CoP
  • Execute repurposing/decom plans - Assess Phase to Post-CoP
  • Cost/schedule monitoring - Assess Phase to Post-CoP

Appraise Phase Key activities/milestones:

  • Late life operating and decommissioning strategies
  • Preliminary cost estimates
  • Stakeholder Engagement Plan
  • Subsurface basis of design


Assess Phase Key activities/milestones:

  • Reuse/repurposing/decom decision
  • Refined cost estimate (Class 3)
  • Contracting strategy
  • Decommissioning Programme (DP) approved by OPRED


Define Phase PHASE Key activities/milestones:

  • Execution contracts awarded
  • Futher refined cost estimate (Class 2) and schedule
  • Permits and consent applications
  • Opportunities for execution ahead of CoP actioned


Execute Phase Key activities/milestones:

  • Execution cost and schedule monitoring and risk management
  • Progress reporting (corporate, JV and regulatory)
  • Lessons learned documenting