{"id":192,"date":"2009-07-22T08:35:10","date_gmt":"2009-07-22T07:35:10","guid":{"rendered":"http:\/\/mccltd.net\/blog\/?p=192"},"modified":"2009-07-22T08:38:45","modified_gmt":"2009-07-22T07:38:45","slug":"calculating-network-availability","status":"publish","type":"post","link":"http:\/\/darenmatthews.com\/blog\/?p=192","title":{"rendered":"Calculating Network Availability"},"content":{"rendered":"<p><strong>Mean Time Between Failures (MTBF)<\/strong><\/p>\n<p>MTBF is a basic measure of reliability for components that are able to be repaired. It is the number of hours that pass before a component or system fails. It is a commonly-used variable in network availability analyses and reports.<!--more--><\/p>\n<p><a href=\"http:\/\/darenmatthews.com\/blog\/wp-content\/uploads\/2009\/07\/mtbf.jpg\" target=\"_blank\"><img loading=\"lazy\" class=\"alignnone size-medium wp-image-195\" title=\"mtbf\" src=\"http:\/\/darenmatthews.com\/blog\/wp-content\/uploads\/2009\/07\/mtbf-300x135.jpg\" alt=\"mtbf\" width=\"300\" height=\"135\" srcset=\"http:\/\/darenmatthews.com\/blog\/wp-content\/uploads\/2009\/07\/mtbf-300x135.jpg 300w, http:\/\/darenmatthews.com\/blog\/wp-content\/uploads\/2009\/07\/mtbf.jpg 721w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>MTBF may be calculated as the inverse of the failure rate for constant failure rate systems. For example: If a component has a failure rate of 2 failures per million hours, the MTBF would be the inverse of that failure rate.<\/p>\n<p>MTBF = (1,000,000 hours) \/ (2 failures) = 500,000 hours<\/p>\n<p><strong>Mean Time To Failure (MTTF)<\/strong><\/p>\n<p>MTTF is a basic measurement of reliability for systems which are non-repairable (such as the battery in a UPS). It is the mean time expected until the first failure of a piece of equipment. MTTF is a statistical value and is meant to be the mean over a long period of time and large number of units.<\/p>\n<p>For constant failure rate systems, MTTF is the inverse of the failure rate. If failure rate is in failures\/million hours, MTTF = 1,000,000 \/ Failure Rate for components with exponential distributions.<\/p>\n<p><em>Technically MTBF should be used only in reference to repairable items, while MTTF should be used for non-repairable items. However, MTBF is commonly used for both repairable and non-repairable items.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Mean Time Between Failures (MTBF) MTBF is a basic measure of reliability for components that are able to be repaired. It is the number of hours that pass before a component or system fails. It is a commonly-used variable in network availability analyses and reports.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[10],"tags":[],"_links":{"self":[{"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/192"}],"collection":[{"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=192"}],"version-history":[{"count":3,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/192\/revisions"}],"predecessor-version":[{"id":194,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/192\/revisions\/194"}],"wp:attachment":[{"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=192"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=192"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=192"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}