https://www.infra-repository.org/oiar-2013/index.php?action=history&feed=atom&title=Property%3AAvailabilityProperty:Availability - Revision history2026-05-06T13:06:57ZRevision history for this page on the wikiMediaWiki 1.40.0https://www.infra-repository.org/oiar-2013/index.php?title=Property:Availability&diff=95&oldid=prevJan Schoonderbeek: start2012-11-11T23:22:21Z<p>start</p>
<p><b>New page</b></p><div>{{Maturity|3}}<br />
{{Pageheaderbox<br />
|pagetype=<br />
|pagename=Availability<br />
|doctype=Quality Attribute<br />
|version=0.1<br />
|owner=J.A.H. Schoonderbeek<br />
}}<br />
__SHOWFACTBOX__<br />
A facility's/products Availability, denoted as a single [[Has type::string]], determines to what degree a facility/product is functioning correctly, and is able to provide sufficient capacity to handle requested use in a timely fashion (within pre-defined service windows). In general, the more robust a facility of product is built, the higher the degree of availability that can be guaranteed. The most common practices in enhancing robustness are the use of redundant components to construct a facility, and/or using a redundant set of facilities to construct a product.<br />
<br />
Defined values for Availability:<br />
{| class="table" style="text-align:center" border="1" cellspacing="0" cellpadding="5"<br />
!style="background:#{{BGColour03}}; color:#2a2a38"|ordinal<br />
!style="background:#{{BGColour03}}; color:#2a2a38"|value<br />
!style="background:#{{BGColour03}}; color:#2a2a38"|meaning<br />
|-<br />
|{{QAlevelordinal|qa=Availability|level=NS}}<br />
|[[allows value::NS]]<br />
|[[Quality Attribute NS|{{QAleveldescription|qa=Availability|level=NS}}]]<br />
|-<br />
|{{QAlevelordinal|qa=Availability|level=Best-Effort}}<br />
|[[allows value::Best-Effort]]<br />
|[[Availability Best-Effort|{{QAleveldescription|qa=Availability|level=Best-Effort}}]]<br />
|-<br />
|{{QAlevelordinal|qa=Availability|level=Medium}}<br />
|[[allows value::Medium]]<br />
|[[Availability Medium|{{QAleveldescription|qa=Availability|level=Medium}}]]<br />
|-<br />
|{{QAlevelordinal|qa=Availability|level=High}}<br />
|[[allows value::High]]<br />
|[[Availability High|{{QAleveldescription|qa=Availability|level=High}}]]<br />
|}<br />
<br />
The table below provides an overview of these classes and the provisions that should be made to get a facility or Product in a certain class:<br />
{| class="table" style="text-align:center" border="1" cellspacing="0" cellpadding="5"<br />
!style="background:#{{BGColour03}}; color:#2a2a38"|Provision<br />
!style="background:#{{BGColour03}}; color:#2a2a38"|Best-Effort<br />
!style="background:#{{BGColour03}}; color:#2a2a38"|Medium<br />
!style="background:#{{BGColour03}}; color:#2a2a38"|High<br />
|-<br />
|Single facility/solution, on a single location<br />
|√<br />
|X<br />
|X<br />
|-<br />
|Redundant or highly resilient facility/solution,<br>on a single location<br />
|√<br />
|√<br />
|X<br />
|-<br />
|Redundant facility/solution, on two or more locations<br />
|X<br />
|√<br />
|√<br />
|-<br />
|Fail-over<br />
|none<br />
|manual, active-passive<br />
|automatic, active-active<br />
|-<br />
|}</div>Jan Schoonderbeek