I wrote this eBook for a software client based on the appropriate persona, available technical materials and interviews with internal subject matter experts. The client used this eBook for their content marketing lead generation campaigns targeted to international manufacturers.
Measuremen Systems Analysis Training ModuleFrank-G. Adler
The Six Sigma Measurement Systems Analysis (MSA) Training Module includes a MS PowerPoint Presentation including 62 slides covering an Introduction to Measurement Systems Analysis - Relevance - Discrimination - Accuracy - Stability - Linearity - Precision, Variable Gage R&R Study, and Attribute Gage R&R Study.
How to Improve Quality and Efficiency Using Test Data AnalyticsTequra Analytics
Discover 8 ways in our guide for advanced manufacturers.
Do you perform advanced manufacturing in an industry such as aerospace, automotive, medical devices or telecoms? Is product testing part of your manufacturing process? If you can answer yes to these questions, keep reading to learn how test data analytics can enable many improvements.
I wrote this eBook for a software client based on the appropriate persona, available technical materials and interviews with internal subject matter experts. The client used this eBook for their content marketing lead generation campaigns targeted to international manufacturers.
Measuremen Systems Analysis Training ModuleFrank-G. Adler
The Six Sigma Measurement Systems Analysis (MSA) Training Module includes a MS PowerPoint Presentation including 62 slides covering an Introduction to Measurement Systems Analysis - Relevance - Discrimination - Accuracy - Stability - Linearity - Precision, Variable Gage R&R Study, and Attribute Gage R&R Study.
How to Improve Quality and Efficiency Using Test Data AnalyticsTequra Analytics
Discover 8 ways in our guide for advanced manufacturers.
Do you perform advanced manufacturing in an industry such as aerospace, automotive, medical devices or telecoms? Is product testing part of your manufacturing process? If you can answer yes to these questions, keep reading to learn how test data analytics can enable many improvements.
Dear All, I have prepared this presentation to get a better understanding of Statistical Process Control (SPC). This is a very informative presentation and giving information about the History of SPC, the basics of SPC, the PDCA approach, the Benefits of SPC, application of 7-QC tools for problem-solving. You can follow this technique in your day to day business working to solve the problems. Thanking you.
Statistical process control (SPC) is a method of quality control which uses statistical methods. SPC is applied in order to monitor and control a process. Monitoring and controlling the process ensures that it operates at its full potential. At its full potential, the process can make as much conforming product as possible with a minimum (if not an elimination) of waste (rework or scrap). SPC can be applied to any process where the "conforming product" (product meeting specifications) output can be measured. Key tools used in SPC include control charts; a focus on continuous improvement; and the design of experiments. An example of a process where SPC is applied is manufacturing lines.
This presentation give you a brief knowledge of, how statistical process control applied in our daily lives, how it works and some of its important formulas,
Este artículo por parte de Minitab Inc., le ayuda a entender cómo mejorar los procesos de inspección.
Para conocer más sobre cómo usar Minitab Statistical Software en procesos de inspección, visite
http://minitab.blackberrycross.com
Dear All, This is very comprehensive training on application of 7QC tools in industry. There is now a common demand in every industry to improve and control the process by achieving product quality with integrity. These 7-QC tools are very useful to fulfil industry demand by controlling the process. I am expecting your kind suggestions and comments to improve my presentation further. Thanks a lot everyone for your time to read this presentation. I hope it will definitely give some value addition in your routine life. Thanking you!
Measurement System Analysis is the first step of the Measure Phase of an improvement project. Before you can pass judgment on the process, you need to ensure that your measurement system is accurate, precise, capable and in control.
From Data to Insights: How IT Operations Data Can Boost QualityCognizant
By leveraging highly-analyzed operational data - the voice of customers, machines and tests - quality assurance (QA) and IT groups can derive major gains in quality of apps and in user experience.
Dear All, I have prepared this presentation to get a better understanding of Statistical Process Control (SPC). This is a very informative presentation and giving information about the History of SPC, the basics of SPC, the PDCA approach, the Benefits of SPC, application of 7-QC tools for problem-solving. You can follow this technique in your day to day business working to solve the problems. Thanking you.
Statistical process control (SPC) is a method of quality control which uses statistical methods. SPC is applied in order to monitor and control a process. Monitoring and controlling the process ensures that it operates at its full potential. At its full potential, the process can make as much conforming product as possible with a minimum (if not an elimination) of waste (rework or scrap). SPC can be applied to any process where the "conforming product" (product meeting specifications) output can be measured. Key tools used in SPC include control charts; a focus on continuous improvement; and the design of experiments. An example of a process where SPC is applied is manufacturing lines.
This presentation give you a brief knowledge of, how statistical process control applied in our daily lives, how it works and some of its important formulas,
Este artículo por parte de Minitab Inc., le ayuda a entender cómo mejorar los procesos de inspección.
Para conocer más sobre cómo usar Minitab Statistical Software en procesos de inspección, visite
http://minitab.blackberrycross.com
Dear All, This is very comprehensive training on application of 7QC tools in industry. There is now a common demand in every industry to improve and control the process by achieving product quality with integrity. These 7-QC tools are very useful to fulfil industry demand by controlling the process. I am expecting your kind suggestions and comments to improve my presentation further. Thanks a lot everyone for your time to read this presentation. I hope it will definitely give some value addition in your routine life. Thanking you!
Measurement System Analysis is the first step of the Measure Phase of an improvement project. Before you can pass judgment on the process, you need to ensure that your measurement system is accurate, precise, capable and in control.
From Data to Insights: How IT Operations Data Can Boost QualityCognizant
By leveraging highly-analyzed operational data - the voice of customers, machines and tests - quality assurance (QA) and IT groups can derive major gains in quality of apps and in user experience.
According to our customer surveys and confirmed by industry statistics, manual testers spend 50-70% of their effort on finding and preparing appropriate test data. Considering the fact that manual testing still accounts for 80+% of test operation efforts, up to half (!) of the overall testing effort goes into dealing with test data.
Find out how Tosca Testsuite can help you to lower the maintenance effort of your test data and operating costs of your test environment while building an efficient test data management strategy.
Meeting the challenges to adopt visual production management systems hms-whit...Ariel Lerer
This White Paper will provide an essential understanding of different initiatives towards having a Visual Production Management system, (VPMS), in a manufacturing environment. Also insights about why? and how? to implement a VPMS, highlighting the benefits of taking these actions, and further across your environment creating a learning organization.
Download from www.hmswebsite.com/vpms-white-paper/
Cpk indispensable index or misleading measure? by PQ SystemsBlackberry&Cross
Capability analysis is a set of calculations used to assess whether a system is able to meet a set of requirements. Customers, engineers, or managers usually set the requirements, which can be specifications, goals, aims, or standards.
The primary reason for doing a capability analysis is to answer the question: Can we meet customer requirements? To be more specific: Can our system produce consistently within tolerances required by the customer now and in the future?
Capability analysis involves two entities: 1) the producer and 2) the consumer. The consumer sets the requirements and the producer must be able to meet the requirements.
Read More.
PQ Systems is a partner of Blackberry&Cross, since 2006.
Visit: http://www.BBCross.com
Lecture 3
Statistical Process
Control (SPC)
Data collection for Six SigmaData are simply facts and figures without context or interpretation.Information refers to useful or meaningful patterns found in the data.Knowledge represents information of sufficient quality and/or quantity that actions can be taken based on the information.If data are not collected and used wisely, their vary existence can lead to activities that are ineffective and possibly even counterproductive.An organization collects data & reacts whenever an out-of-specification condition occurs.
“Common cause” & “ special cause” variation
There are two causes of process variations:
1) Common cause variation: This variation is due to the process only. It may not tell you whether the process meets the needs of the customer unless it is compared with the specification. This can be improved by focusing on the process.
2) Special cause variation: This variation is due the individual employee, if the point is beyond specification limits. In this case the focus should be about what happened relative to the individual employee as though it were a “special” condition.
Attribute versus Variable Data
Attribute data: It is a data with yes or no decision such as:whether an iten passed or failed a testpass/fail, go/no go gaging, true/false, accept/reject. There are no quantifiable values
Variable data: are related to measurements with quantifiable values such as:Diameter of a part which has been machinedlength or thickness of the machined part
The success of Six SigmaThe success of Six Sigma depends upon knowing the difference between special & common cause variations and how the organization reacts to the data.If the management focuses on wrong cause of variation, it can lead to waste of time (firefighting).It can also effect employee motivation & morale.Reacting to one data point that do not meet the specification limit can be counterproductive and very expensive.Do not use “firefighting” actions just because the data point is out of specification limits. It must first be determined whether the condition is common or special cause.
Example of variability due to common causeControl limits are calculated from the sample data.There are no data points outside the control limits therefore there are no special causes within the data.The source of variation in this case is “common cause” due to process.
Type of firefighting done by management before evaluating the cause of variabilityProduction supervisors might constantly review production output by employee, machine, product line, work shift etc.An administrative assistant’s daily output & memo’s may be monitored.The average time per call may be monitored in a call center.The efficiency of computer programmers may be monitored by tracking “lines of code produced per day”.
All of these actions would be a waste of time if the cause of variability is “common cause” and due to the process rather than individu ...
The Evolution of Digital Control Towers in Supply ChainTredence Inc
Corporations today want to leverage useful applications of the supply chain control tower. Organizations have copious amounts of data across their supply chain and related functions.
Learn more: https://www.tredence.com/solutions/supply-chain-control-tower
Before you can fix a problem, you must first see it. However, the longer you're in the same place, the more difficult it is to see the waste around you.
Taking a 'waste walk' is one way to make the waste visible again. A waste walk is more than just going to the gemba. It is a planned visit to where work is being performed to observe what's happening and to specifically look for waste.
Linda Dodge and Janell Vickers are Lean Six Sigma Black Belts from Catholic Health Partners (CHP). In a webinar hosted by MoreSteam, Linda and Janell shared their experiences utilizing Waste Walks in hospital settings and physician practices to help front line staff open their eyes to find the invisible waste.
These slides will show the following key points will be covered:
The key objectives of a waste walk
Finding your own 'waste eyes' and helping others to find theirs
How to use waste walks to engage employees in problem-solving and operational excellence
A map to conduct your own waste walk
More information:
www.blackberrycross.com
https://www.youtube.com/user/blackberryandcross
Slides from Webcast: Deploying Storytelling at Mercy Health
Stories are powerful change agents. How do you tell a story? How does your organization tell a story? What if we told a story the same way? What if goals were aligned on impactful work?
Join Joe Schultz to hear about Mercy Health's journey to tell stories in an impactful way using an A3 Storyteller. Over the past nine months, the Toledo and Lima regions have set upon a mission to use an A3 Storyteller that combines problem-solving elements from the healthcare industry (SBAR: Situation Background Assessment Recommendation, PDSA, and poster presentation style). Learn from the trials and tribulations that Mercy encountered during the phases of its deployment: assembling the team, designing the tool, piloting with one site, deploying across seven hospitals, and then setting up accountability structures for outcome monitoring.
In this session, the following key points will be covered:
The power of stories, standard work, and making it sticky
How to get senior leaders engaged
Create an A3 your way
Generate momentum around cascading goals / key performance indicators
Create communication strategy and roll-out plan
Create accountability structures and sustaining change
Learn more and download the slides of this webcast:
e-learning course on LEAN Methods:
http://bit.ly/lean-methods-bbcross
All copyrights to MoreSteam LLC. Used here with authorization by MoreSteam.
These slides are part of the Webcast:
A3 Reports: Polishing the Elevator Speech
"So, how's your project going? Hey, I only have 10 minutes, so can you just give me a quick update? No need to spend the time on the detail, just hit the highlights..."
Sound familiar? Maybe it's time for you to use the A3 Report, a Lean tool meant to identify and communicate the critical project information and to facilitate decision-making. The A3 has been widely adopted for use in toll gate project reviews, however, expanding its functionality beyond that realm and getting Belts to internalize 'A3 thinking' can be a formidable challenge.
About the webcast: one-hour Webcast led by Clopay's Tor Chamberlain on how his organization has made great strides in communication and transparency using the A3 Report. There's nothing scary about A3 Reports!
In this session, the following key points will be covered:
Types of projects most suitable for A3s: short-duration Kaizen activities and/or complex DMAIC projects
Use of A3 methodology to communicate effectively to different levels in the organization
Use of A3 methodology to identify and track LSS projects
How to coach A3 thinking
These material is property of MoreSteam LLC. Used with authorization.
Watch the webcast:
Learn more about A3:
www.moresteam.com
www.blackberrycross.com
From unicorns to race horses. Es el momento de Machine Learning para Excelenc...Blackberry&Cross
Desde Minitab Inc., nos llega este excelente contenido para mostrarnos la evolución del mundo digital y cómo sin ser experto en Phyton, C#, C u otros lenguajes, usted puede usar la tecnologia Minitab y elevar su desempeño empresarial a nuevos y mejores niveles.
#Minitabwebinar
Modern tool kit for process excellence, gracias a Minitab Inc.Blackberry&Cross
Del Webinar del mismo nombre, Minitab Inc., aliado de Blackberry&Cross desde 2004 para toda América Central, nos trae estas valiosas ideas sobre como combinar DMAIC con herramientas de Machine Learning.
Excelente contenido.
Descubra más sobre Minitab en http://minitab.blackberrycross.com
Machinelearning: The next step in manufacturing performance Blackberry&Cross
Minitab, nuestro aliado desde 2004, ha dado esta presentación sobre Aprendizaje Automático y aqui les compartimos el futuro.
Haga click, no tanto "code".
Este es un material proporcionado por Prezi.
Blackberry&Cross es aliado de Prezi Business, y queremos ayudarle a ser más exitoso en sus ventas, mercadeo y presentaciones.
Material en idioma portugués
Cpk: indispensable index or misleading measure? by PQ SystemsBlackberry&Cross
Capability analysis is a set of calculations used to assess whether a system is able to meet a set of requirements. Customers, engineers, or managers usually set the requirements, which can be specifications, goals, aims, or standards.
The primary reason for doing a capability analysis is to answer the question: Can we meet customer requirements? To be more specific: Can our system produce consistently within tolerances required by the customer now and in the future?
Capability analysis involves two entities: 1) the producer and 2) the consumer. The consumer sets the requirements and the producer must be able to meet the requirements.
PQ Systems and Blackberry&Cross are partners since 2006.
Visit: http://www.blackberrycross.com
BPM: Business Process Management con FIreStart BPM Suite de PrologicsBlackberry&Cross
Gracias a la alianza Prologics-Blackberry&Cross, usted puede participar de conferencias web, demostraciones y pruebas para implementar y desplegar BPM en su empresa.
Más información en www.BlackberryCross.com
Universidades, Colegios Técnicos, Secundarias académicas, pueden adquirir Snagit, Camtasia, Minitab, Companion y muchos otros software por medio de Blackberry&Cross. Precios especiales para el sector académico.
8 WAYS TO BOOST BUSINESS WITH SMART DATA ANALYSIS: Minitab Insights Promo e-bookBlackberry&Cross
Una serie de casos de éxitos en la solución de problemas, utilizando #smart data, por medio de Minitab Statistical Software.
Blackberry&Cross es el aliado oficial de Minitab Inc., en América Central, desde 2005.
Minitab Power User: Destacar puntos para análisisBlackberry&Cross
El modo "destacado" en Minitab es una poderosa herramienta de visualización de datos, como parte del análisis.
Esta presentación (confeccionado por medio de TheBpr, en 18 segundos) le muestra los pasos.
Más información en www.blackberrycross.com
Four steps to an audit proof measurement system by PQ SystemsBlackberry&Cross
Cuatro pasos para lograr un sistema de medición a "prueba de balas".
Mejore sus sistema de medición, asegure su calidad.
Gracias a PQ Systems, aliado de Blackberry&Cross desde 2006.
Más información: http://www.blackberycross.com
Advertencia: esta presentación contiene videos incrustados que podría no estar disponibles en el formato que accede. Para poder ver los videos escriba a soporte@blackberrycross.com
Confeccione una catapulta económica y divertida para enseñar a sus estudiantes principios estadísticos, como DOE (Diseño de Experimentos), pruebas de hipótesis, regresión, ANOVA, entre otros. Inspirada en los artículos del Blog de Minitab, esta presentación de Blackberry&Cross se puede complementar con artículos y consejos prácticos disponibles en http://i4is.blackberrycross.com. Un juego ideal para profesores y estudiantes de cursos de estadística, ingeniería industrial, calidad y productividad, o programas LEAN Six Sigma.
Advanced DOE with Minitab (presentation in Costa Rica)Blackberry&Cross
DOE:Diseño de Experimentos
Esta presentación fue dada por Minitab Inc., en Costa Rica, en el año 2007, como parte del trabajo de Blackberry&Cross, socio de Minitab Inc., para América Central, en la promoción y difusión de temas STEM, y de la comercialización de Minitab Statisitical Software.
Licenciamiento concurrente para reducir costos : un caso-ejemplo Blackberry&Cross
Su equipo de trabajo necesita software. Pero hay limitantes de presupuesto. Todos las tenemos.
Quizás es conveniente explorar cómo el licenciamiento concurrente puede ayudar a disminuir costos, y sobre todo inversión inicial. De esta forma, usted dota a sus equipos de las herramienta necesarias, y hace un mejor manejo del dinero a la vez.
Esta presentación invita a estudiantes de ingeniería industrial a revisar la necesidad de fortalecer, reforzar, varias destrezas técnicas en su carrera. Las destrezas mencionadas se derivan de investigaciones y evidencia empírica recolectada por Blackberry&Cross y SixSigmaCR.com entre 2005 y 2015 en América Central.
Esta presentación es sin fines de lucro y cuando se expone se debe contar con un expositor(a) certificado por Blackberry&Cross para poder elaborar.
Igualmente se realiza un #quiz para ilustrar a los estudiantes cómo está bien vivir al tanto de la cultura pop, deportiva o política, pero como también es fundamental conocer la obra, y su aplicación, de grandes personajes de la ingeniería de mejoramiento continuo y calidad.
Se adjuntan notas de descargo sobre uso de imágenes, derechos de marca y otros.
Resumen de ponencia presentada por Blackberry&Cross (http://www.bbcross.com) acerca de la LEAN (LEAN Six Sigma) en un contexto de sostenibilidad, conservación y mejor manejo de recursos ambientales, como parte integral de la gestión de mejoramiento continuo. Se mencionan errores o contradicciones encontrados en investigación de campo.
Blackberry&Cross sus accionistas, trabajadores, aliados ni proveedores se hacen responsables del uso que el lector(a) haga de este material.
Para mayor información contacte a Blackberry&Cross. soporte@blackberrycross.com
Presentación que acompaña a la ponencia dada por Matt Savage, de PQ Systems, durante la conferencia LEAN Six Sigma Online 2014, organizada por Blackberry&Cross.
Más información: http://lssc.blackberrycross.com
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
An Approach to Detecting Writing Styles Based on Clustering Techniquesambekarshweta25
An Approach to Detecting Writing Styles Based on Clustering Techniques
Authors:
-Devkinandan Jagtap
-Shweta Ambekar
-Harshit Singh
-Nakul Sharma (Assistant Professor)
Institution:
VIIT Pune, India
Abstract:
This paper proposes a system to differentiate between human-generated and AI-generated texts using stylometric analysis. The system analyzes text files and classifies writing styles by employing various clustering algorithms, such as k-means, k-means++, hierarchical, and DBSCAN. The effectiveness of these algorithms is measured using silhouette scores. The system successfully identifies distinct writing styles within documents, demonstrating its potential for plagiarism detection.
Introduction:
Stylometry, the study of linguistic and structural features in texts, is used for tasks like plagiarism detection, genre separation, and author verification. This paper leverages stylometric analysis to identify different writing styles and improve plagiarism detection methods.
Methodology:
The system includes data collection, preprocessing, feature extraction, dimensional reduction, machine learning models for clustering, and performance comparison using silhouette scores. Feature extraction focuses on lexical features, vocabulary richness, and readability scores. The study uses a small dataset of texts from various authors and employs algorithms like k-means, k-means++, hierarchical clustering, and DBSCAN for clustering.
Results:
Experiments show that the system effectively identifies writing styles, with silhouette scores indicating reasonable to strong clustering when k=2. As the number of clusters increases, the silhouette scores decrease, indicating a drop in accuracy. K-means and k-means++ perform similarly, while hierarchical clustering is less optimized.
Conclusion and Future Work:
The system works well for distinguishing writing styles with two clusters but becomes less accurate as the number of clusters increases. Future research could focus on adding more parameters and optimizing the methodology to improve accuracy with higher cluster values. This system can enhance existing plagiarism detection tools, especially in academic settings.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
DESIGN AND ANALYSIS OF A CAR SHOWROOM USING E TABS
Five costly mistakes applying spc [whitepaper]
1. Five Costly Mistakes Applying SPC
(and how to avoid them)
By Steve Daum
I have daily conversations with manufactures who are using statistical process
control (SPC). I field questions from plant managers, quality managers, engineers,
supervisors, and plant production workers about the challenges of applying these
quality methods. Of the mistakes I witness in the application of SPC, the following
are the five most prevalent and costly.
#1 Capability before stability
Capability is a critical metric, and capability statistics are often an important part
of a supply chain conversation. Customers want assurance that your processes
are capable of meeting their requirements, and their requirements are often
communicated with tolerances or specifications.
Customers often specify a Cpk or Ppk value that you must meet, and because they
put such importance on it, these capability statistics become your primary concern
in quality improvement efforts.
A representative of a manufacturer of springs, a tier 3 supplier to the automotive
industry, recently contacted me. They were puzzled because they had calculated
an “acceptable” Cpk of 1.2 but had produced products that fell outside the customer
specifications, as well as having an unusually high defects per million (Dpm) rate.
www.pqsystems.com
800.777.3020
1
2. When a control chart of the process was produced, it became obvious that the
manufacturer had not assessed process stability prior to calculating Cpk. Looking
at the control chart on the following page, it is obvious that the process is not in
control. Stability must be assessed before a capability study is done. Without this
prerequisite, the Cpk statistics are not reliable.
www.pqsystems.com
800.777.3020
2
3. Without his determination of stability, any reliance on Cpk values is premature. The
first issue to be addressed is getting to a stable, predictable process. Knowledge
is power, but action gets things done. Building control charts into your analytical
process on the front end can prevent costly mistakes such as scrap, shipping
unacceptable product, or even the dreaded recall.
When pressure is applied, perhaps prior to an audit or as part of contract
negotiations, the need to produce and use Cpk value can be hard to resist. It is
important to reinforce at every opportunity that stability (control) is required before
capability is studied. Require suppliers and staff to accompany a capability statistics
in any context with the relevant control chart showing that the process was in
control (stable) prior to doing the capability analysis.
The Automotive Industry Action Group (AIAG) asserts that one of the three
conditions that must be satisfied for capability analysis is process stability,
specifically “the process from which the data come is statistically stable, that is, the
normally accepted SPC rules must not be violated.”1
www.pqsystems.com
800.777.3020
3
4. #2 Misuse of control limits
Producing control charts does not guarantee accurate process feedback. There
are many subtleties with the application of control limits that are easy to get wrong.
Here are a few common errors:
Computing wrong limit values with a home grown tool
Excel is a great software tool. It is so flexible that you can mimic almost any
software application, including SPC software, using Excel. It’s difficult to resist
the temptation to use it exclusively because it is already on your computer. The
calculations for control limits are not difficult, but they do have much room for error.
Choices such as How to calculate Sigma? Which sigma should be used? Does
subgroup size affect Sigma? and How many values should be used for a Moving
Range? must be made. The exact answers can be computed in a spreadsheet, but
time and time again I have seen examples where the numbers are just plain wrong,
often resulting in audit failures. If you use a home grown tool for SPC, proceed with
caution. Validate the numbers for multiple use cases; these include large numbers,
small numbers, negative numbers, samples with missing observations, samples
with known assignable causes, etc.
Never computing control limits
The decision to compute control limits should be a deliberate one, even if your SPC
software automatically computes limits for you. Someone with solid SPC training,
knowledge of the process, and knowledge of the measurement being studied
should decide when the limits will be computed and what data will be used. Once
a trial set of control limits is computed and it is clear that the process is stable (the
control chart has no out-of-control conditions), this set of control limits can become
the official set of control limits to be used on the chart.
www.pqsystems.com
800.777.3020
4
5. Never re-computing control limits
Once you have established a good official set of control limits for the control chart,
the chart can be deployed and used as a process monitoring tool. However, this is
not the end of the story. If you are focused on continuous improvement, you should
be focused on centering the process on the target value, reducing variation, or both.
If you are successful in your improvement efforts over the course of a year, then the
control limits you computed in January will not reflect how the process is running
in September. A deliberate re-computing of the control limits to establish the new
baseline is in order.
Waiting to have enough data to compute control limits
Whether you have a small amount of data or a great deal of data, computing
baseline control limits will almost always provide benefits. There are many
guidelines, such as waiting until you have at least 25 subgroups gathered over a
normal course of production. If you don’t have much data yet, however, reasonable
control limits can be computed even with small amounts of data.
www.pqsystems.com
800.777.3020
5
6. Confusing specification limits with control limits
Specifications, also known as tolerances, indicate what your customer requires.
These are important numbers, but they are not control limits. Control limits are
computed based on data from your process. Control limits reflect how your process
behaves. I often see line charts with horizontal specification lines at the upper and
lower specification values. This type of chart might provide value in some situations,
but it should never be confused with a control chart.
The reason for doing a control chart (with control limits) is to reduce the chance of
two types of errors:
1) Overcontrol, or adjusting the process when it should be left alone
2) Undercontrol, or not adjusting the process when it should be adjusted
The specification lines cannot give you this information. If your sample size is one,
they can tell if one part is outside the customer specifications, but they do not relay
any information about the variation in your process over time.
www.pqsystems.com
800.777.3020
6
7. #3 Not assessing the measurement system
If you are applying SPC, you are measuring things. Do you know how well you are
measuring? This is a critical area that is easily overlooked when you are focused on
SPC, but even the best application of SPC tools can be undermined when the ability
to measure things is uncertain.
Your ability to measure accurately and consistently is critical to SPC. In the control
chart shown below, everything is in control.
www.pqsystems.com
800.777.3020
7
8. Next, look at the results of an R&R study done with a measurement device. By
looking at the Total Variation (TV) for example, we know that the measured values
could be significantly different from the actual values.
The next chart shows the possible range of the REAL values from this measurement
process. As you can see, if the measurements have too much variation, a process
exhibiting complete stability can result in costly out-of-spec product.
www.pqsystems.com
800.777.3020
8
9. If you don’t assess your ability to make good measurements, the confidence in
your SPC results is reduced. Simply put, garbage in, garbage out. Utilizing the set
of tools known as Measurement Systems Analysis (MSA) can help ensure quality
measurements are fed to your SPC output.
#4 Failure to manage the measurement system
How well do you manage your measurement equipment? What is the calibration in-
terval? What steps are checked during a calibration? What is the history of calibra-
tion for a given device? What master gages are used for the calibration, and have
those devices been calibrated? Do you have systems in place to ensure that gages
which are past due for calibration or preventative maintenance are not used?
www.pqsystems.com
800.777.3020
9
10. In addition to performing measurement systems analysis, you need to properly
manage your measuring devices. Software applications designed for this purpose,
such as PQ Systems’ GAGEpack®, can help you with assessing and managing
your measurement system.
#5 Wasting time creating and viewing too many charts for
too few signals
Technology has made it easier to create and deploy SPC charts on anything and
everything. While advantages to this development abound, the amount of time
spent by valuable workers doing repetitive, non value-added, SPC-related work can
be costly.
If you need to monitor dozens or even hundreds of SPC charts, you need to seek
methods of scaling your SPC application. Consider the time it might take to do
these steps:
1. Find the chart of interest
2. Display the chart
3. Analyze the chart
4. Decide if action is needed or not
One large textile manufacturer’s business goals justified monitoring 300 SPC
charts. They needed a method of scaling their global SPC application efficiently.
Even their most efficient, well-trained worker who was able to complete the four
steps in just one minute was spending five hours of work simply monitoring charts!
Rather than invest their analysts’ time and attention viewing hundreds of charts—
most of which reflect processes that are operating in control--they implemented
software that uses scanning techniques to surface only the charts that need
attention.
Utilizing an automated approach to process monitoring can amplify your ability
to pay attention to key metrics without dragging quality workers away from more
important activities.
www.pqsystems.com
800.777.3020
10
11. In the example below, 31 charts have been created and put into an SQCpack
StatBoard®. The StatBoard has scanned each chart for out-of-control conditions
and ranked the charts based on the number of conditions found. The analyst can
focus on the red and perhaps yellow charts and ignore the remaining ones. The
interval at which the StatBoard runs is set by the user. In the case of the textile
manufacturer, it is running every two hours.
Dr. Donald Wheeler describes SPC as “a way of thinking with some tools attached.”
Often, when I see these mistakes being made, the root cause is too much focus on
the tools of SPC and not enough focus on the SPC way of thinking. The common
thread among the five mistakes is an underlying need for more education. Through
continuing education, this SPC way of thinking can become embedded in the
manufacturing culture.
www.pqsystems.com
800.777.3020
11
1
Statistical Process Control: SPC (second edition), Automotive Industry Action
Group, 2005, p. 139.
12. About the author
Steve Daum is Director of Development for PQ Systems. He has more
than 30 years of experience with statistical process control, control
charts, and control charting software. Steve has published papers in
a variety of professional journals and has led multiple seminars and
presented on statistical process control and issues related to quality to a
variety of audiences in the U.S., England, and South Africa. To learn more about PQ
Systems’ software applications SQCpack and GAGEpack, visit
www.pqsystems.com.
www.pqsystems.com
800.777.3020
12