Glossary term
CDOS (combat day of supply)
TERM SUMMARY
CDOS stands for combat day of supply. NATO defines it as the total amount of supplies required to support one day of combat, calculated by applying the intensity factor to a standard day of supply.
- Why it matters
- CDOS stands for combat day of supply . It is NATO logistics terminology for the total amount of supplies required to support one day of combat.
- Category
- Canadian government procurement terminology
- Reference role
- This term page is designed to be linkable, crawlable, and easy to quote or summarize.
CDOS stands for combat day of supply. It is NATO logistics terminology for the total amount of supplies required to support one day of combat. NATO calculates it by applying the intensity factor to a standard day of supply, so the figure reflects how hard forces are expected to fight rather than a flat daily average.
The term sits alongside the day of supply (DOS), the standard daily requirement. A DOS describes what a force needs on an ordinary day. A CDOS adjusts that requirement for the expected intensity of combat. Planners use the two measures to decide how much materiel must be held and moved to support a force. The definition appears in the NATO Logistics Handbook, and the abbreviation is listed in the AAP-15 Glossary of NATO acronyms and abbreviations.
How CDOS differs from a standard day of supply
The difference between the two terms is the intensity factor. A standard day of supply is the baseline daily requirement. A combat day of supply starts from that baseline and applies the intensity factor, which accounts for the expected level of combat activity. The result is the total quantity of supplies needed to support one day of combat.
- DOS: a standard daily requirement.
- CDOS: the standard daily requirement adjusted for expected combat intensity.
Keeping the two terms separate matters in planning documents. A figure stated in days of supply and a figure stated in combat days of supply do not describe the same quantity of materiel.
Where the term is defined in NATO references
Two NATO documents establish the meaning directly. The AAP-15 glossary lists the abbreviation CDOS with the expansion “combat day of supply.” The NATO Logistics Handbook gives the full definition, including the use of the intensity factor.
NATO also maintains NATOTerm, its official terminology database of non-classified military terminology relevant to the Alliance. The NATOTerm database is the place to check how NATO currently words its terms. The AAP-15 glossary and the handbook are the documents to cite when a bid or planning document uses the abbreviation.
Days of supply in theatre planning
NATO logistics planning uses days of supply to determine the quantities held in theatre. This covers the initial phase of a mission and the expected sustainment period. The NATO Logistics Handbook sets out this approach. Expressing stockholding in days of supply gives planners a common unit across commodities and nations. The combat day of supply extends that unit to periods of fighting, where consumption is expected to run above the standard rate.
What CDOS means for a supplier bidding on Canadian public contracts
CDOS is a NATO planning term. Suppliers who work on defence requirements, or who partner with prime contractors serving allied forces, may see it in logistics and sustainment documents. When a solicitation refers to days of supply or combat days of supply, read the quantities, assumptions and intensity factors set out in the tender documents themselves, and ask the contracting authority for clarification through the stated question process before the deadline.
Tender notices for federal requirements are published on CanadaBuys. Information on defence business opportunities is available from Canada Economic Development for Quebec Regions. Bid teams should keep the NATO definition on file so that proposal writers use DOS and CDOS consistently and do not treat them as interchangeable.