{"id":"wpc-tech100-article-085-en","slug":"control-charts-for-wpc-profile-dimensions","locale":"en","url":"https://woodplasticcomposite.net/guides/control-charts-for-wpc-profile-dimensions/","title":"Control charts for WPC profile dimensions","answer":"A control chart can help distinguish expected process variation from signals requiring investigation. It is not the same thing as a product tolerance band.","author":"NFC & WPC Knowledge Reference","faqIds":["wpc-tech100-faq-085-en"],"tagIds":[],"noindex":false,"related":["wpc-tech100-article-086-en"],"version":1,"modified":"2026-10-15","reviewer":"","sections":[{"id":"technical-context","text":"Control limits describe behaviour estimated from a suitable process baseline; specification limits describe acceptance requirements. Confusing them can hide an unstable process or cause unnecessary adjustments to normal variation.","heading":"Technical context","references":[],"url":"https://woodplasticcomposite.net/guides/control-charts-for-wpc-profile-dimensions/#technical-context"},{"id":"verification-plan","text":"Choose the chart and sampling arrangement with competent statistical input. Record changes in tooling, material and operating conditions. Investigate signals using the production history rather than changing machine settings reflexively after every high or low reading.","heading":"What to measure and document","references":[],"url":"https://woodplasticcomposite.net/guides/control-charts-for-wpc-profile-dimensions/#verification-plan"},{"id":"practical-decision","text":"Use the chart as part of a response plan that includes product identification and disposition. A stable process can still fail the specification, while an apparently acceptable sample can come from an unstable process. Both process behaviour and product conformity matter.","heading":"Implications for development and specification","references":[],"url":"https://woodplasticcomposite.net/guides/control-charts-for-wpc-profile-dimensions/#practical-decision"},{"id":"reading-scope","text":"General engineering-statistics guidance; not a WPC product standard. Use the linked work as related reading. The practical checks above are editorial recommendations, not reported test results or a substitute for product qualification.","heading":"Related reading and evidence limits","references":[1],"url":"https://woodplasticcomposite.net/guides/control-charts-for-wpc-profile-dimensions/#reading-scope"}],"seoTitle":"Control charts for WPC profile dimensions | WPC Reference","topicIds":[],"published":"2026-10-15","tableText":"Review step | Evidence to retain\nMaterial and geometry | Exact specimen or product identity\nVerification | Method, conditions and individual observations\nDecision | Approved scope and documented limitations","takeaways":"Control limits describe behaviour estimated from a suitable process baseline; specification limits describe acceptance requirements.\nChoose the chart and sampling arrangement with competent statistical input.\nUse the chart as part of a response plan that includes product identification and disposition.","aiAssisted":true,"categoryId":"wpc-tech100-category-4","reviewedAt":"","change_note":"New focused technical draft; not a product certification or production recipe.","description":"A control chart can help distinguish expected process variation from signals requiring investigation.","heroImageId":"","referenceIds":["wpc-tech100-ref-statistics"],"review_status":"AI-assisted English editorial draft. Human technical review has not been recorded.","table_caption":"Evidence checklist for control charts for wpc profile dimensions","seoDescription":"A control chart can help distinguish expected process variation from signals requiring investigation.","translationGroup":"wpc-tech100-085-2026","references":[{"url":"https://www.itl.nist.gov/div898/handbook/","type":"web","title":"NIST engineering statistics handbook","noindex":false,"accessed":"2026-10-14","seoTitle":"NIST engineering statistics handbook","publisher":"NIST","description":"Related reading; scope and limitations are identified in each article.","seoDescription":"Related reading; scope and limitations are identified in each article."}],"faqs":[{"question":"What evidence is needed for control charts for WPC profile dimensions?","answer":"Choose the chart and sampling arrangement with competent statistical input. Record changes in tooling, material and operating conditions. Investigate signals using the production history rather than changing machine settings reflexively after every high or low reading."}]}