COCOMO (constructive cost model)

COCOMO stands for Constructive Cost Model. It is a parametric model for estimating the effort, schedule and cost of a software-development project, using inputs such as the expected size of the software and a set of cost drivers. Barry W. Boehm developed it, and the model family is documented in the COCOMO reference entry.

NATO lists the acronym in its glossary of abbreviations, AAP-15, as "constructive cost model". The same entry gives the French equivalent as "modèle constructif d'établissement des coûts". Software teams, defence organizations and space agencies have used COCOMO as a planning tool for estimating software work before it begins.

What COCOMO estimates and how it works

COCOMO is a parametric cost estimation method. Rather than building a price from a line-by-line list of tasks, it applies a mathematical relationship between project characteristics and the work required. The main outputs are effort, schedule and cost for a planned software-development activity.

Size is the central input. The model combines the expected size of the software with other drivers that describe the project, and produces an estimate from those values. NASA's Software Engineering Handbook describes COCOMO II as a model for estimating the cost, effort and schedule of a planned software-development activity, and explains how it supports planning. The NASA handbook page on COCOMO II is a useful starting point for the detail.

COCOMO 81 and COCOMO II

The original model is generally called COCOMO 81. The revised family is COCOMO II. The COCOMO II Model Definition Manual uses the word "COCOMO" collectively to cover both COCOMO 81 and COCOMO II, so the bare acronym can refer to either generation.

COCOMO II has three submodels that offer increasing fidelity as planning and design mature:

• Applications Composition, used for early work on projects built largely from existing components.
• Early Design, used once requirements are explored but the architecture is not settled.
• Post-Architecture, used when the project has a defined architecture and the estimate can be more detailed.

The earlier COCOMO 81 family included Basic and Intermediate models. A U.S. Department of Defense technical report, available through DTIC, documents the use of both for software-cost estimation.

COCOMO in NATO terminology

NATO's AAP-15 glossary treats COCOMO as a standard glossary term and attributes the entry to NASG. The entry establishes what the letters stand for in English and French. It does not, on its own, create a NATO-wide requirement to use the model in procurement.

Bid teams working on allied or defence-related software opportunities may meet the acronym in technical or cost documents. Knowing the expansion and the model family lets a team read those references correctly.

What COCOMO means for suppliers bidding on Canadian public contracts

COCOMO is an estimation technique, and a supplier can use it internally to size and price a software project. The supplier's obligations come from the solicitation itself. Each tender states what pricing, cost information and deliverables a bidder must submit, and bidders must follow those instructions.

Review the full solicitation documents for every software opportunity, including the pricing basis and any cost-reporting terms. Current opportunities are listed on CanadaBuys. If your team builds estimates with COCOMO, keep the inputs and assumptions documented so you can explain how the figures were reached if the buyer asks.