Attributes of good software

As well as the services that it provides, software products have a number of other
associated attributes that reflect the quality of that software. These attributes are not
directly concerned with what the software does. Rather, they reflect its behaviour
while it is executing and the structure and organisation of the source program and
associated documentation. Examples of these attributes (sometimes called nonfunctional
attributes) are the software s response time t9 a user query and the understandability
of the program code.
The specific set of attributes that you might expect from a software system obviously
depends on its application. Therefore, a banking system must be secure, an interactive game must be responsiv,e, a telephone switching system must be reliable,
and so on.

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Maintainability

Software ~;hould be written in such a way that it may
evolve to meet the changing needs of customers. This is a
critical attribute because software change is an inevitable
consequence of a changing business environment
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Dependability

Software dependability has a range of characteristics,
including reliability, security and safety. Dependable
software !ihould not cause physical or economic damage
in the eVE,nt of system failure.
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Efficumcy

Software should not make wasteful use of system
resources such as memory and processor cycles. Efficiency
therefore includes responsiveness, processing time,
memory utilisation, etc.
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Usability

Software must be usable, without undue effort, by the type of
user for ",hom it is designed. This means that it should have
an appropriate user interface and adequate documentation.