View source for Property:Scalability

{{Maturity|4}}
{{Pageheaderbox
|pagetype=
|pagename=Scalability
|doctype=Quality Attribute
|version=1.0
|owner=J.A.H. Schoonderbeek
}}
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The scalability of a facility, denoted as a single [[Has type::string]], determines how easy or difficult it will be to alter its capacity. There are two strategies available to promote scalability, namely facilitating the possibility of either internal or external scaling.
* Internal scalability is achieved by the expandability (or reduction) of individual components making up the solution (Scaling Up or Down); an example would be the addition of extra RAM in a server.
* External scalability is achieved by using more (or less) components in parallel (Scaling Out or In); an example would be the addition of extra web servers behind a load balancer.
When determining the scalability of a solution, it is advisable to devote extra attention to interfaces and aggregation points, because this is where most bottlenecks and integration issues will occur.

Defined values for Scalability:
{| class="table" style="text-align:center" border="1" cellspacing="0" cellpadding="5"
|- style="background:#{{BGColour03}}; color:#{{FGColour04}}"
!ordinal
!value
!meaning
|-
|{{QAlevelordinal|qa=Scalability|level=NS}}
|[[allows value::NS]]
|[[Quality Attribute NS|{{QAleveldescription|qa=Scalability|level=NS}}]]
|-
|{{QAlevelordinal|qa=Scalability|level=fixed}}
|[[allows value::fixed]]
|[[Scalability fixed|{{QAleveldescription|qa=Scalability|level=fixed}}]]
|-
|{{QAlevelordinal|qa=Scalability|level=up}}
|[[allows value::up]]
|[[Scalability up|{{QAleveldescription|qa=Scalability|level=up}}]]
|-
|{{QAlevelordinal|qa=Scalability|level=up and down}}
|[[allows value::up and down]]
|[[Scalability up and down|{{QAleveldescription|qa=Scalability|level=up and down}}]]
|-
|{{QAlevelordinal|qa=Scalability|level=out}}
|[[allows value::out]]
|[[Scalability out|{{QAleveldescription|qa=Scalability|level=out}}]]
|-
|{{QAlevelordinal|qa=Scalability|level=out and back}}
|[[allows value::out and back]]
|[[Scalability out and back|{{QAleveldescription|qa=Scalability|level=out and back}}]]
|-
|{{QAlevelordinal|qa=Scalability|level=up and out}}
|[[allows value::up and out]]
|[[Scalability up and out|{{QAleveldescription|qa=Scalability|level=up and out}}]]
|-
|{{QAlevelordinal|qa=Scalability|level=up, down, out and back}}
|[[allows value::up, down, out and back]]
|[[Scalability up, down, out and back|{{QAleveldescription|qa=Scalability|level=up, down, out and back}}]]
|}