ACT-KA-000206 · Rev. 1 · IMO GHG Measures
CII vs EEXI
EEXI is a technical or design-efficiency requirement for existing ships. CII is an annual operational carbon intensity rating. EEXI asks whether the ship's technical efficiency meets the required standard. CII asks how efficiently the ship actually operated during the year.
A ship can be EEXI compliant but still receive a poor CII rating if it is operated inefficiently, waits for long periods, consumes excessive fuel or has poor hull/engine performance.
Difficulty: BeginnerReviewed: 2026-07-24
CII vs EEXIEnergy Efficiency Existing Ship IndexCarbon Intensity IndicatorIMO GHG measures
Frequently Asked Questions
Is EEXI calculated every year?
EEXI is generally a technical compliance assessment connected to ship certification. CII is calculated and rated annually.
Can engine power limitation help EEXI?
Yes, engine or shaft power limitation is one of the practical measures used by some ships to meet required EEXI.
Does EEXI guarantee a good CII rating?
No. EEXI compliance does not guarantee good operational performance. CII still depends on annual fuel, distance, operating profile and data quality.
Should technical and commercial teams review CII together?
Yes. Technical condition affects fuel efficiency, while voyage orders, speed, waiting time and cargo employment also drive CII.
Technical Explanation
EEXI:
• Applies to existing ships as a technical energy efficiency index.
• Is linked to design/technical characteristics, installed power, capacity and speed assumptions.
• May be met through measures such as engine/shaft power limitation or technical efficiency improvements.
CII:
• Applies as an annual operational rating.
• Uses actual annual emissions and transport work.
• Is recorded as A, B, C, D or E.
• Requires corrective action for repeated D or any E trigger.
Checklists
• EEXI technical file available
• Required and attained EEXI recorded
• Power limitation arrangements documented where fitted
• CII reference line configured separately
• Annual CII monitoring active
• SEEMP Part III aligned with operational measures
Practical Case Studies
A vessel installs shaft power limitation to comply with EEXI. During the following year, it spends many weeks waiting at anchorage and then sails at high speed to recover schedules. EEXI remains compliant, but CII rating deteriorates because operational fuel per transport work increases.
KPI Monitoring
• EEXI compliance status
• CII annual rating
• Power-limited operating events
• Fuel per nautical mile
• Schedule recovery high-speed days
Related Actinium-SM Modules
• EEXI compliance record storage
• CII operational dashboard
• Technical and voyage performance link
• SEEMP action register
- EEXI compliance record storage
- CII operational dashboard
- Technical and voyage performance link
- SEEMP action register
References
• IMO EEXI and CII FAQ: distinction between attained EEXI and annual operational CII.
• IMO energy efficiency page: EEXI technical framework and CII operational framework.
Use Actinium-SM to keep EEXI evidence and annual CII performance visible together.
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Last review: 2026-07-24