A specification tree shows all
specifications
A specification often refers to a set of documented requirements to be satisfied by a material, design, product, or service. A specification is often a type of technical standard.
There are different types of technical or engineering specificati ...
of a technical system under development in a hierarchical order.
For a
spacecraft system it has the following levels:
* System (requirements) specification - generated by customer
** System (design to) specification - generated by system responsible prime contractor
*** Subsystem specifications - generated by system responsible prime contractor
**** Assembly
[An assembly level is defined as intermediate level when the subsystem contractor prefers to contract a group of units with complex interfaces to another contractor (for instance the ]operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...
and subsystem application software
Application may refer to:
Mathematics and computing
* Application software, computer software designed to help the user to perform specific tasks
** Application layer, an abstraction layer that specifies protocols and interface methods used in a c ...
can be an assembly of the data management subsystem). specifications - generated by subsystem responsible contractors
***** Unit specifications - generated by subsystem (or assembly) responsible contractors.
References
Product development
Systems engineering
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