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RE: [ba-ohs-talk] Solving complex problems - Requirements and Constraints


Dennis E. Hamilton wrote:    (01)

> Do you know somewhere that has "requirements and constraints" laid out in
> more detail?  I want to raise my competence in that area.    (02)

Not that I can put my hands on immediately.    (03)

<opinion>
A requirement is something a system must do or not do, e.g.: The system
shall support Unicode file names.
A constraint is something the system has to live with, e.g.: Files are
limited to 2GB in size.
Other constraints are added as derived requirements during design and
implementation. In "Design by Contract" there are pre-conditions,
post-conditions, and invariants. These are all constraints that arise
because of the design or implementation, e.g.: Topic names are limited to 55
characters.
</opinion>    (04)

Thanks,    (05)

Garold (Gary) L. Johnson    (06)