{"id":12556,"date":"2025-10-21T23:45:56","date_gmt":"2025-10-21T21:45:56","guid":{"rendered":"https:\/\/sxe-consulting.com\/?page_id=12556"},"modified":"2025-10-21T23:45:56","modified_gmt":"2025-10-21T21:45:56","slug":"method-5-why","status":"publish","type":"page","link":"https:\/\/sxe-consulting.com\/en\/glossaire-industriel\/methode-5-why\/","title":{"rendered":"Method 5 Why"},"content":{"rendered":"

Visit The 5 Whys<\/strong> (or 5 Why<\/em>) is an iterative interrogation technique used in the Lean Management<\/strong> and the\u2019Continuous Improvement (KAIZEN)<\/strong>. Its objective is to dig beyond the symptom of a problem to identify its root cause. Cause Racine<\/strong> (Root Cause<\/em>).<\/p>\n

<\/p>\n

In-depth definition :<\/strong> Developed and popularized within the Toyota Production System (TPS), this method is based on the principle that by asking \u201cWhy?\u201d<\/strong> repeatedly (usually five times, hence the name), the team can trace the causal chain back from the visible problem to the systemic failure or lack of Standardization<\/strong> that made the problem possible. It's a simple and effective tool, often used in conjunction with the Ishikawa diagram<\/strong> or during the D4 (Determine Root Cause)<\/strong> a 8D analysis<\/strong>, because it requires no complex statistical analysis.<\/p>\n

The Five-Step Process (Industrial Example)<\/strong><\/h3>\n

Applying the method is a logical progression, where the answer to a \u201cWhy?\u201d question becomes the object of the next question.<\/p>\n

Initial problem (Symptom) :<\/strong> The n\u22183 assembly machine broke down this morning, leading to a production stoppage.<\/p>\n

    \n
  1. Why did the machine break down?<\/strong>\n
      \n
    • Answer:<\/em> Motor protection fuse blown.<\/li>\n<\/ul>\n<\/li>\n
    • Why did the fuse blow?<\/strong>\n
        \n
      • Answer:<\/em> The engine has overheated.<\/li>\n<\/ul>\n<\/li>\n
      • Why did the engine overheat?<\/strong>\n
          \n
        • Answer:<\/em> The lubrication system has not supplied enough oil.<\/li>\n<\/ul>\n<\/li>\n
        • Why didn't the lubrication system supply enough oil?<\/strong>\n
            \n
          • Answer:<\/em> The Preventive Maintenance<\/strong> forgot to top up the oil on its last run.<\/li>\n<\/ul>\n<\/li>\n
          • Why did the technician forget to top up?<\/strong>\n
              \n
            • Answer (Cause Racine):<\/em> Visit Standardization<\/strong> workstation (maintenance check sheet) does not include a specific line for checking oil level, and the machine has no visible sight glass (lack of Visual Management<\/strong>).<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

              Conclusion:<\/strong> The visible cause was the blown fuse (the symptom). The root cause is a defect in the maintenance procedure standard<\/strong> and visual aids.<\/p>\n

              Role in Operational Excellence<\/strong><\/h3>\n

              The power of The 5 Whys<\/strong> lies in its ability to direct action towards eliminating the root cause, thus guaranteeing effective solutions.<\/p>\n

                \n
              • Eliminating Recurring Problems :<\/strong> By tackling the root cause (e.g. updating the standard or adding a Poka-Yoke<\/strong>), the team ensures that the problem will not recur, a key principle of the Lean Six Sigma<\/strong>.<\/li>\n
              • Simplicity and speed:<\/strong> It can be carried out quickly in the workplace (Gemba<\/em>) by the operators themselves, making it easier for them to take ownership of the\u2019Continuous Improvement<\/strong>.<\/li>\n
              • PDCA power supply :<\/strong> Once the root cause has been identified, the solution is implemented (Do<\/strong>), the results are verified (Check<\/strong>), and the new standard is established (Act<\/strong>), completing the PDCA (Plan-Do-Check-Act)<\/strong>.<\/li>\n<\/ul>\n

                It is essential to stop when the cause found is operable<\/strong> by the team and that it's a system failure (not personal blame).<\/p>\n

                In conclusion, the The 5 Whys<\/strong> is the simplest and most powerful interrogation tool for moving from symptom to systemic cause, ensuring that the actions of the\u2019 Continuous improvement<\/strong> generate sustainable gains in operating performance.<\/p>\n

                <\/p>\n

                <\/p>\n

                <\/p>","protected":false},"excerpt":{"rendered":"

                La M\u00e9thode des 5 Pourquoi (ou 5 Why) est une technique it\u00e9rative d’interrogation utilis\u00e9e dans le Lean Management et l’Am\u00e9lioration Continue (KAIZEN). Son objectif est de creuser au-del\u00e0 du sympt\u00f4me d’un probl\u00e8me pour en identifier la Cause Racine (Root Cause) sous-jacente.<\/p>","protected":false},"author":1,"featured_media":0,"parent":12324,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_sitemap_exclude":false,"_sitemap_priority":"","_sitemap_frequency":"","footnotes":""},"definition":[99],"class_list":["post-12556","page","type-page","status-publish","hentry","definition-definition"],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/sxe-consulting.com\/en\/wp-json\/wp\/v2\/pages\/12556","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sxe-consulting.com\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sxe-consulting.com\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sxe-consulting.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sxe-consulting.com\/en\/wp-json\/wp\/v2\/comments?post=12556"}],"version-history":[{"count":0,"href":"https:\/\/sxe-consulting.com\/en\/wp-json\/wp\/v2\/pages\/12556\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/sxe-consulting.com\/en\/wp-json\/wp\/v2\/pages\/12324"}],"wp:attachment":[{"href":"https:\/\/sxe-consulting.com\/en\/wp-json\/wp\/v2\/media?parent=12556"}],"wp:term":[{"taxonomy":"definition","embeddable":true,"href":"https:\/\/sxe-consulting.com\/en\/wp-json\/wp\/v2\/definition?post=12556"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}