HOOD is a method of hierarchical decomposition of the design into software units based on identification of objects, classes and operations reflecting problem domain entities or more abstract objects related to digital programming entities. It is intended for the Architectural Design, Detailed Design and coding for software to be developed in programming languages such as Ada, C, or FORTRAN, as well as in object oriented languages such as C++, Ada95 or Eiffel.

The HOOD method comprises textual and associated diagrammatic representations allowing formal refinement, automated checking, user customizable documentation generation and target language source code generation.

The HOOD method was developed in 1987 under European Space Agency (ESA) contract A0/1-1890/86/NL/MA by a consortium of CISI, CRI A/S and Matra Marconi Space. HOOD has been selected by ESA projects as the design method for the Architectural Design phase. Since, HOOD has been selected by large, complex or long lived project from aerospace, defense and industry.

Since 1989 the HOOD Manuals have been developed, in response to user experience, by the HOOD Working Group comprising representatives of ESTEC, Columbus and Hermes projects and later under control by the HOOD USER GROUP (HUG).

In 1991, the HUG was setup as a non profit organisation aiming to provide support for sharing experience and to control the evolution of the method. The HUG was organized in a STEERING GROUP (HSG) in charge of administrative issues, and in a TECHNICAL GROUP (HTG) in charge of all technical issues possibly delegating work to specific WORKING GROUPs.

The HOOD REFERENCE MANUAL Issue 3.1 was further developed in 1991 by the HOOD TECHNICAL GROUP and approved for two years by vote by the HOOD USER GROUP at the Pisa (Italy) april 3rd 1992 HUG meeting. The HOOD REFERENCE MANUAL Release 4 was further developed in 1994 by the HOOD TECHNICAL GROUP and approved for two years by vote by the HOOD USER GROUP at the London (UK) HUG meeting in februray 1995.

Initially developed for Ada83 program developments, HOOD is now targeting Ada95 as well as more classical and object oriented languages and systems. HOOD puts the emphasis on interface and behaviour definition and mastering, some issues that were rather neglected by other design methods.

Moreover HOOD is the framework for mastering and integration of the development of software components which may be developped with different target language and technologies (MMI generators, DBMS interface generators, rule system and KBS generators). HOOD is thus supporting complex programming and development in the large, relying on code generator technology from high level and when possible, formal notations. As a result HOOD fills primarily the needs of prime contractors and integrators. Providing a standard inter-change format, the HOOD method addresses also pragmatic reuse, tool inter-operability and design perenniality.

HOOD is thus the method of choice for large, long-lived projects where reuse, reliability and maintenability are key issues.

Since 1999, the method is considered stable. The UML wave has hidden the HOOD methods, but many UML profiles have borrowed the best of HOOD (HRT-UML, AADL).