{"id":4608,"date":"2026-08-12T14:47:41","date_gmt":"2026-08-12T12:47:41","guid":{"rendered":"https:\/\/ellistat.com\/?post_type=guide-dutilisateur&p=4608"},"modified":"2026-08-12T14:47:41","modified_gmt":"2026-08-12T12:47:41","slug":"reliability-estimate","status":"publish","type":"guide-dutilisateur","link":"https:\/\/ellistat.com\/en\/guide-dutilisateur\/estimation-de-fiabilite\/","title":{"rendered":"Reliability Estimate"},"content":{"rendered":"

This is the main entry: it applies a lifespan rule to your data.<\/p>\n\n\n\n

1. Select the input format<\/h2>\n\n\n\n

Five formats, depending on the actual format of your data. That's the first decision you need to make.<\/p>\n\n\n\n

Format<\/strong><\/td>Table Structure<\/strong><\/td>Use Cases<\/strong><\/td><\/tr><\/thead>
Periods and Censorship<\/strong><\/td>Start of period, end of period, number of failures, number of censored observations<\/td>Data Already Aggregated by Interval<\/td><\/tr>
Values and Censorship<\/strong><\/td>Uptime, Outages, Numbers<\/td>Laboratory Tests<\/td><\/tr>
Sale and Return Dates<\/strong><\/td>Date of sale, date of return, numbers, censorship<\/td>Item-by-Item Traceability<\/td><\/tr>
Date of Sale and Downtime<\/strong><\/td>Date of sale, uptime, numbers, censorship<\/td>A variation on the previous one, useful for cars, where we think in terms of kilometers rather than time<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\n

\ud83d\udca1 Don't convert your data to fit a specific format\u2014choose the format that matches what you have. Every manual conversion is an opportunity to lose data.<\/p>\n<\/blockquote>\n\n\n\n

\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n

2. Configure the analysis<\/h2>\n\n\n\n
    \n
  • Type of Analysis<\/strong>\u00a0: 2- or 3-parameter Weibull, Kaplan-Meier; ;<\/li>\n\n\n\n
  • Calculation method<\/strong>\u00a0:\u00a0maximum likelihood<\/strong>\u00a0or\u00a0regression<\/strong>\u00a0;<\/li>\n\n\n\n
  • Confidence Level<\/strong>\u00a0of the interval; ;<\/li>\n\n\n\n
  • Maximum x-coordinate of the graphs<\/strong>, to adjust the display.<\/li>\n<\/ul>\n\n\n\n
    \n

    \ud83d\udca1\u00a0Plausibility or regression?<\/strong>\u00a0<\/p>\n\n\n\n

    Maximum likelihood is statistically more efficient and handles censoring better; it is the default choice. Regression, which fits a straight line to the Weibull plot, is more visual and makes it easier to explain the results to others. On actual data, the two methods converge; if they diverge significantly, it is a sign that the distribution is a poor fit.<\/p>\n<\/blockquote>\n\n\n\n

    3. Kaplan-Meier<\/h2>\n\n\n\n

    Kaplan-Meier does not adjust no law<\/strong> : It constructs the observed survival curve, step by step, taking censoring into account.<\/p>\n\n\n\n

    \"\"<\/figure>\n\n\n\n
      \n
    • Use\u00a0Weibull<\/strong>\u00a0when we want to extrapolate, make a 5-year forecast based on 1 year of historical data, or obtain an interpretable \u03b2.<\/li>\n\n\n\n
    • Use\u00a0Kaplan-Meier<\/strong>\u00a0when we want to describe something without making assumptions, or when the shape of the curve is clearly irregular.<\/li>\n<\/ul>\n\n\n\n

      Visit Kaplan-Meier survival comparison<\/strong> compares two groups: two suppliers, two versions, two usage conditions. It\u2019s the right tool for answering the question, \u00abDoes the new version hold up better than the old one?\u00bb.<\/p>\n\n\n\n

      4. Read the results<\/h2>\n\n\n\n

      The Weibull paper<\/strong> aligns the data points if the model fits well. A distinct curvature suggests trying a 3-parameter Weibull model, or indicates a mixture of two failure modes.<\/p>\n\n\n\n

      The\u00a0hazard graph<\/strong>\u00a0shows the evolution of the failure rate over time; the direct reading of the regime is described by \u03b2.<\/p>\n\n\n\n

      \n

      \u26a0\ufe0f Mixing two failure modes in the same dataset results in a poor fit and an intermediate \u03b2 that describes neither one nor the other. If you know the failure modes, Separate the data before adjusting it<\/strong>. A \u03b2 of 1.2 may mask a \u03b2 of 0.6 for infant mortality plus a \u03b2 of 3 for wear and tear.<\/p>\n<\/blockquote>\n\n\n\n

      \n

      Ellistat flags cases where analysis is not possible: \u00abNo failures available for Weibull analysis with this selection\u00bb; if no failures have been observed, no distribution can be fitted.<\/p>\n<\/blockquote>","protected":false},"featured_media":0,"menu_order":50,"template":"","meta":{"_acf_changed":true},"menu-guide-dutilisateur":[36],"class_list":["post-4608","guide-dutilisateur","type-guide-dutilisateur","status-publish","hentry","menu-guide-dutilisateur-9-fiabilite"],"acf":[],"yoast_head":"\nEstimation de fiabilit\u00e9 - Ellistat<\/title>\n<meta name=\"description\" content=\"Choisissez le bon format de donn\u00e9es, ajustez une loi de Weibull ou une courbe de Kaplan-Meier, et interpr\u00e9tez vos r\u00e9sultats de fiabilit\u00e9 pas \u00e0 pas.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/ellistat.com\/en\/users-guide\/reliability-estimate\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Estimation de fiabilit\u00e9 - Ellistat\" \/>\n<meta property=\"og:description\" content=\"Choisissez le bon format de donn\u00e9es, ajustez une loi de Weibull ou une courbe de Kaplan-Meier, et interpr\u00e9tez vos r\u00e9sultats de fiabilit\u00e9 pas \u00e0 pas.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/ellistat.com\/en\/users-guide\/reliability-estimate\/\" \/>\n<meta property=\"og:site_name\" content=\"Ellistat\" \/>\n<meta property=\"og:image\" content=\"https:\/\/ellistat.com\/wp-content\/uploads\/fiabilite3.png\" \/>\n\t<meta property=\"og:image:width\" content=\"150\" \/>\n\t<meta property=\"og:image:height\" content=\"372\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/ellistat.com\\\/guide-dutilisateur\\\/estimation-de-fiabilite\\\/\",\"url\":\"https:\\\/\\\/ellistat.com\\\/guide-dutilisateur\\\/estimation-de-fiabilite\\\/\",\"name\":\"Estimation de fiabilit\u00e9 - Ellistat\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/ellistat.com\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/ellistat.com\\\/guide-dutilisateur\\\/estimation-de-fiabilite\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/ellistat.com\\\/guide-dutilisateur\\\/estimation-de-fiabilite\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/ellistat.com\\\/wp-content\\\/uploads\\\/fiabilite3.png\",\"datePublished\":\"2026-08-12T12:47:41+00:00\",\"description\":\"Choisissez le bon format de donn\u00e9es, ajustez une loi de Weibull ou une courbe de Kaplan-Meier, et interpr\u00e9tez vos r\u00e9sultats de fiabilit\u00e9 pas \u00e0 pas.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/ellistat.com\\\/guide-dutilisateur\\\/estimation-de-fiabilite\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/ellistat.com\\\/guide-dutilisateur\\\/estimation-de-fiabilite\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/ellistat.com\\\/guide-dutilisateur\\\/estimation-de-fiabilite\\\/#primaryimage\",\"url\":\"https:\\\/\\\/ellistat.com\\\/wp-content\\\/uploads\\\/fiabilite3.png\",\"contentUrl\":\"https:\\\/\\\/ellistat.com\\\/wp-content\\\/uploads\\\/fiabilite3.png\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/ellistat.com\\\/guide-dutilisateur\\\/estimation-de-fiabilite\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Accueil\",\"item\":\"https:\\\/\\\/ellistat.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Estimation de fiabilit\u00e9\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/ellistat.com\\\/#website\",\"url\":\"https:\\\/\\\/ellistat.com\\\/\",\"name\":\"Ellistat\",\"description\":\"La suite qualit\u00e9 de l'industrie m\u00e9canique\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/ellistat.com\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Reliability Estimation - Ellistat","description":"Choose the right data format, fit a Weibull distribution or a Kaplan-Meier curve, and interpret your reliability results step by step.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/ellistat.com\/en\/users-guide\/reliability-estimate\/","og_locale":"en_US","og_type":"article","og_title":"Estimation de fiabilit\u00e9 - Ellistat","og_description":"Choisissez le bon format de donn\u00e9es, ajustez une loi de Weibull ou une courbe de Kaplan-Meier, et interpr\u00e9tez vos r\u00e9sultats de fiabilit\u00e9 pas \u00e0 pas.","og_url":"https:\/\/ellistat.com\/en\/users-guide\/reliability-estimate\/","og_site_name":"Ellistat","og_image":[{"width":150,"height":372,"url":"https:\/\/ellistat.com\/wp-content\/uploads\/fiabilite3.png","type":"image\/png"}],"twitter_card":"summary_large_image","twitter_misc":{"Est. reading time":"3 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/ellistat.com\/guide-dutilisateur\/estimation-de-fiabilite\/","url":"https:\/\/ellistat.com\/guide-dutilisateur\/estimation-de-fiabilite\/","name":"Reliability Estimation - Ellistat","isPartOf":{"@id":"https:\/\/ellistat.com\/#website"},"primaryImageOfPage":{"@id":"https:\/\/ellistat.com\/guide-dutilisateur\/estimation-de-fiabilite\/#primaryimage"},"image":{"@id":"https:\/\/ellistat.com\/guide-dutilisateur\/estimation-de-fiabilite\/#primaryimage"},"thumbnailUrl":"https:\/\/ellistat.com\/wp-content\/uploads\/fiabilite3.png","datePublished":"2026-08-12T12:47:41+00:00","description":"Choose the right data format, fit a Weibull distribution or a Kaplan-Meier curve, and interpret your reliability results step by step.","breadcrumb":{"@id":"https:\/\/ellistat.com\/guide-dutilisateur\/estimation-de-fiabilite\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/ellistat.com\/guide-dutilisateur\/estimation-de-fiabilite\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/ellistat.com\/guide-dutilisateur\/estimation-de-fiabilite\/#primaryimage","url":"https:\/\/ellistat.com\/wp-content\/uploads\/fiabilite3.png","contentUrl":"https:\/\/ellistat.com\/wp-content\/uploads\/fiabilite3.png"},{"@type":"BreadcrumbList","@id":"https:\/\/ellistat.com\/guide-dutilisateur\/estimation-de-fiabilite\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Accueil","item":"https:\/\/ellistat.com\/"},{"@type":"ListItem","position":2,"name":"Estimation de fiabilit\u00e9"}]},{"@type":"WebSite","@id":"https:\/\/ellistat.com\/#website","url":"https:\/\/ellistat.com\/","name":"Ellistat","description":"The quality suite for the mechanical engineering industry","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/ellistat.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"}]}},"_links":{"self":[{"href":"https:\/\/ellistat.com\/en\/wp-json\/wp\/v2\/guide-dutilisateur\/4608","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ellistat.com\/en\/wp-json\/wp\/v2\/guide-dutilisateur"}],"about":[{"href":"https:\/\/ellistat.com\/en\/wp-json\/wp\/v2\/types\/guide-dutilisateur"}],"wp:attachment":[{"href":"https:\/\/ellistat.com\/en\/wp-json\/wp\/v2\/media?parent=4608"}],"wp:term":[{"taxonomy":"menu-guide-dutilisateur","embeddable":true,"href":"https:\/\/ellistat.com\/en\/wp-json\/wp\/v2\/menu-guide-dutilisateur?post=4608"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}