• Newsroom
  • Join us!
  • Newsletter
  • Kontakt
  • English English English en
  • Deutsch Deutsch German de
Experts Institut
  • Business Consulting
    • Business Solutions
      • Digitization
      • Sustainability Corporate strategy
      • Management systems
      • Project management
      • Strategy & Performance
      • Transformation & Leadership
  • GXP Consulting
    • GMP Beratung
      • Audits & inspections
      • GMP/GXP training courses
      • GMP Aircheck4
      • Continuous Manufacturing
  • Industries
    • Pharma
    • Service providers & trade
    • Automotive
    • FOOD & BEVERAGES
    • Financial service providers & insurances
    • Informationstechnik (IT)
    • Aerospace
  • Academy
    • Individuelle Inhouse-Schulungen
      • GMP/GXP training courses
    • Experts Institut Events
      • Academy
    • Direkt buchen
      • Live-Events
      • On-Demand Webinar
  • Kunden
  • Über uns
    • Über uns
      • Guideline
      • Portrait
      • Team
      • Geschäftsführung
      • Vision
      • Events
      • History Experts Institute
      • Sustainability at the Experts Institute
      • Social responsibility
    • Wissen
      • Newsroom
      • GMP Glossary
      • FAQ – Frequently asked questions in the GMP environment
      • Videos
    • Services
      • Retaxation
  • Click to open the search input field Click to open the search input field Search
  • Menu Menu
  • Link to LinkedIn
  • Link to Xing
GMP, GXP

Sensible limit values for process capability

Prozessfähigkeit
  • Zuletzt aktualisiert vor:9 months 
  • Lesezeit:3Minuten
  • Anzahl Wörter:384Wörter

The calculation of the process capability in the form of the process capability index (Ppk or Cpk) sets the scatter of the individual results and the position of the mean value in relation to the specification limits. The higher the process capability index, the further away the individual results are from the specification limits.

Calculation of the process capability index:

The following parameters are included in the calculation of the process capability index:

  • Mean value (μ)
  • Standard deviation of the mean value (σ)
  • Upper and lower specification limit (OSG and USG)

The first step is to calculate the process capability indices “Cpo” and “Cpu” for the upper and lower specification limits:

Cpo = (OSG – μ)/(3σ) OSG = upper specification limit

Cpu = (μ – USG)/(3σ) USG = lower specification limit

Cpk = min(Cpo, Cpu)

In a second step, the lower value (Cpk = smallest process capability value) of the two values is selected:

The calculation of meaningful Cpk values is only possible from 25 – 30 individual values.

Sample calculation:

Investigated quality characteristic: content of a medicinal product

Specification limits: 95 – 105 mg

Average value: 98 mg

Standard deviation: 0.5 mg

Cpo = (105 mg – 98 mg)/(3×0.5 mg) = 4.7

Cpu = (98 mg – 95 mg)/( 3×0.5 mg) = 2.0

Cpk = min(Cpo, Cpu) = 2.0

But what do the Cpk values obtained mean?

Cpk = 1.00

If 1 million units are checked, 2699 faulty units would be found. The distance of the mean value to the next specification limit corresponds to 3 times the standard deviation (3σ) of the values.

Cpk = 1.33

If 1 million units are checked, 66 faulty units would be found. The distance of the mean value to the next specification limit corresponds to 4 times the standard deviation (4σ) of the values.

Cpk = 1.67

If 1 million units are checked, no faulty units would be found. The distance of the mean value to the next specification limit corresponds to 5 times the standard deviation (5σ) of the values.

Cpk = 2.00

If 1 million units are checked, no faulty units would be found. The distance of the mean value to the next specification limit corresponds to 6 times the standard deviation (6σ) of the values.

The limit values selected for the CpK value should be determined on a risk basis. This means that the more critical a quality characteristic is, the higher the acceptance criterion for the CpK value should be.

Read our entire blog: https://experts-institut.de/newsroom/
And feel free to follow us on LinkedIn: https://de.linkedin.com/company/expertsinstitut

Dipl. Ing. Wolfgang Rudloff
Dipl. Ing. Wolfgang Rudloff

Vita

  • 30 Jahre Erfahrung in der pharamzeutischen Industrie

Expertise:

  • Geprüfter Sachverständiger für Reinraumtechnik und GMP-Management
  • Lead Auditor und Gutachter

Stationen:

  • Technischer Leiter
  • COO / Gesamt-Herstellungsleiter
  • Remidiation-Manager
  • Projektleiter Neubau/GMP-Upgrade
  • Management-GMP-Beratung
  • Fachautor, GMP-Trainer, Mediator
18. February 2023/by Dipl. Ing. Wolfgang Rudloff
Tags: GMP, GXP
Share this entry
  • Share on Facebook
  • Share on X
  • Share on WhatsApp
  • Share on LinkedIn
  • Share by Mail
https://experts-institut.com/wp-content/uploads/2023/02/Blog-JK-061120-1-980x513-1.webp 513 980 Dipl. Ing. Wolfgang Rudloff https://experts-institut.de/wp-content/uploads/2023/02/GEMI_Logo_Slogan_color_RGB.webp Dipl. Ing. Wolfgang Rudloff2023-02-18 16:52:152024-10-29 07:59:27Sensible limit values for process capability
You might also like
GMP Guidance for Artificial Intelligence (AI), Machine Learning (ML) and Digital Transformation: How it Finally Begins to Enter the EU GMP Guide
GMP GMP reagent management: Many unspoken rules?
Cultures in Audits & Inspections Crossing Cultures in Audits and Inspections
Audits GxP audits: How important are they and how are they conducted?
Cannabis GMP standards for medicinal cannabis: guaranteeing quality in an emerging industry

Eintrag teilen
  • Share on Facebook
  • Share on WhatsApp
  • Share on LinkedIn
  • Link to Xing

Dipl. Ing. Wolfgang Rudloff
/dipl-ing-wolfgang-rudloff/https://www.linkedin.com/in/wolfgang-rudloff-57876b48/?originalSubdomain=demailto:

Dipl. Ing. Wolfgang Rudloff

CEO
Experts Institut

Inhalt

Neustadt

Experts Institut Beratungs GmbH
Kirchwiesenstrasse 5

D-67434 Neustadt a. d. Weinstraße

Phone: +49 (0)6321 969210
E-mail: info@expertsinstitut.de

Fax: +49 (0)6321 9692199

Bamberg

Experts Institut Beratungs GmbH
Untere Sandstraße 53

D-96047 Bamberg

Phone: +49 (0)951 51939330
E-mail: info@expertsinstitut.de

Freiburg

Experts Institut Beratungs GmbH
Habsburgerstrasse 101a

D-79104 Freiburg im Breisgau

Phone: +49 (0)6321 9692120
E-mail: info@expertsinstitut.de

St. Gilgen (Austria)

Experts Institut Beratungs GmbH
Helenenstrasse 16

A-5340 St. Gilgen, Austria

Tel.: +43 (0)6227 21068
E-mail: info@expertsinstitut.de

kununu
  • Link to LinkedIn
  • Link to Xing

© 2024 Experts Institut Beratungs GmbH
  • Imprint
  • Data protection
  • AGBs
  • Cookie Directive (EU)
Link to: Proof of process stability Link to: Proof of process stability ProzessstabilitätProof of process stability
Scroll to top Scroll to top Scroll to top