To explain the various statistical techniques that we have developed or used over the past 20 years, we have written several books, reference manuals, and booklets. In addition to these, we have created several unique types of charting paper to help you graph and analyze process data.
|
IQI Product Price List (in U.S. Dollars)
|
|
$99.95
139.00
4.00
19.95
19.95
14.95
4.00
4.00
4.00
4.00
4.00
4.00
5.00
|
|
Measuring Process Capability
by Davis Bothe, 900 pages, soft cover, $99.95
This book was chosen by ASQ as one of the five books every quality practitioner should have on his or her book shelf (Quality Progress magazine, April, 2004, page 32). It was also picked as one of the reference best books when doing design for six sigma (Six Sigma Forum magazine, August, 2002, page 48).
Most manufacturers talk about the importance of providing customer satisfaction, but very few actually measure how well they are achieving this important objective. One method for quantifying exactly how well a process meets customer requirements is to measure its inherent capability.
In this book's 900 pages, Davis Bothe draws heavily on his twenty-nine years of manufacturing experience to demonstrate how process capability can be assessed for almost every type of process (machining and assembly, discrete and continuous), including those generating variable data (with either a normal or a non-normal output distribution) or attribute data. More than 70 different capability measures are included, with plenty of real-life case studies to demonstrate the proper application and interpretation of these techniques. Flowcharts are included to aid in the correct choice and application of these methods.
In addition, the book contains several unique measures to deal with special situations not covered in any other text: unilateral specifications; cases where the target for the process average is not the middle of the tolerance; short production runs; autocorrelated data; GD&T; tool wear; setup variation; products having within-piece variation; and features without specifications. An extensive list of references and exercises are provided at the end of each chapter for those interested in pursuing advanced study.
The result of four years of intensive work and research, this is the only reference available that provides a unified system of measuring process capability. Aided by more than 450 illustrations, this book concisely (yet thoroughly) describes all capability measures, using consistent terminology, and with a minimum amount of theory. It makes an excellent reference book for all practicing black belts.
This updated and revised (2001) soft-cover edition (7 by 9.5 inches) clearly explains how the correct application of capability measures can benefit shop-floor personnel, enlighten managers and, most importantly, satisfy your customers.
|
Description of Each Chapter
1. Introduction: the value in being able to quantify the ability of a process to satisfy customers.
2. Importance of Process Stability: a review of variable-data control charts, the power of control charts, difference between control limits and specification limits, and why capability cannot be estimated for an unstable process.
3. Estimating Process Parameters: shows how to estimate the process average, short-term (within subgroup) and long-term (overall) process standard deviation from variable-data charts.
4. Defining Process Capability: definition given for both bilateral and unilateral specifications, potential versus performance capability, selecting critical characteristics, establishing capability goals, fallacy of the common-goal policy, flowchart of steps for conducting capability studies, and when to update a capability study.
5. Measuring Potential Capability: the 6 sigma spread, Cr, Pr, Cst, and Pst indices, also measures for unilateral specifications, including flowcharts for selecting the proper potential capability measure.
6. Measuring Performance Capability: the Zlsl, Zusl, Zmin, Zmax, Cpl, Cpu, Ppl, Ppu, Cpk, Ppk, Cpm, Ppm, Cpg, Ppg, Cpmk, and Ppmk indexes as well as the k, kl, ku, and kt factors for evaluating process aim. Includes measures for specifications where the target for the process average is not the middle of the tolerance and how to estimate the percentage of nonconforming parts, ppm.
7. Checking the Normality Assumption: understanding histograms, normal probability paper (NOPP), skewness, kurtosis, median ranks, simulating effect of process changes on capability, using NOPP to set control limits for IX & MR charts when output distribution is non-normal, goodness-of-fit tests (Chi-squared and Anderson-Darling), and curve fitting non-normal distributions.
8. Measuring Capability for Non-Normal Distributions: using percentiles to estimate equivalent capability metrics, using the percentage nonconforming to estimate ppm levels, as well as the recently-developed equivalent Ppk index.
9. Measuring Capability with Attribute Data: review of np, p, c, and u charts, estimating equivalent Ppk for these charts, defects per unit (dpu) versus defects per opportunity (dpo), capability at the unit level versus capability at the opportunity level, flowchart for selecting the proper attribute chart.
10. Conducting Machine Capability Studies: control chart method, sequential s test, setting machine capability goals based on process capability goals, how to eliminate gage variation from estimates of machine capability.
11. Calculating Confidence Bounds for Capability Measures: confidence bound formulas are provided for almost every measure of capability covered in this book.
12. Combining Capability Measures: Average Cpk for the combined output of many different streams, Product Cpk for multiple product characteristics done on one process, Product Cpk for a machining or assembly line, Normalized Cpk for comparing complex products, and the radar graph for simultaneously displaying the actual capability of several characteristics vs. their respective capability goals.
13. Assessing Capability for Special Cases: repeating trends (tool wear); setup-to-setup variation; autocorrelated data (continuous processes); short production runs (job shops, JIT applications); products having within-piece variation; features with GD&T for hole center; features without tolerances.
14. Understanding the Six-Sigma Philosophy: a static versus dynamic process, understanding the 1.5 sigma shift, capability goals for six-sigma quality, actions required for achieving six-sigma quality.
This book was printed in the USA.
|
Pricing
Price per Book
Quantity
1 - 4
5 - 9
10 - 19
20 and over
|
(U.S. Dollars)
$99.95
$95.95
$90.95
$85.95
|
Please add $5.05 postage and handling for each book ordered -- overseas orders must add $14.05 per book (allow 2 weeks for delivery in the U.S., 6 weeks for overseas deliveries). Check, made out to IQI, or purchase order must accompany written orders. All checks must be in U.S. dollars, payable at a U.S. bank. We now accept VISA and MasterCard credit cards. Please call 262-375-8868 to place your order.
|
Reducing Process Variation
by Davis Bothe, 1134 pages, soft cover, $139
'Simply astonishing in scope and depth.' Review appearing in Amazon.com.
Used in many black belt and green belt training programs.
As consultants, we are frequently hired by manufacturing companies to help them solve chronic quality problems. After working on many such projects, we realized we went through a fairly similar sequence of steps to zero in on the major cause of process variation. We began writing down these steps, refining them over the years until they evolved into the DOT*STAR problem-solving strategy that is featured in this book.
Although there are many strategies available for resolving a wide variety of problems, the DOT*STAR strategy is specifically designed for solving chronic quality problems in manufacturing, primarily for processes involving machining, fabrication, and assembly. We believe this focus on a certain area is one of the reasons why this approach is so very effective, yet easy to apply, even for small to medium sized companies. You will discover this strategy is not just a collection of statistical tools, but a structured set of operating
instructions detailing how to systematically and logically apply these tools in the correct sequence, and at the proper time, to help you uncover major sources of chronic process variation. Numerous real-life case studies illustrate how to successfully apply the strategy.
This book was written for those who must resolve quality problems on the shop floor; assemblers, machine operators, maintenance personnel, quality engineers, manufacturing engineers, SPC facilitators, green belts, black belts, quality control managers, and supplier quality engineers. Keeping this audience in mind, we limited the statistical techniques presented in the book to those that are easy to understand. Thus, an extensive knowledge of statistics is not required to successfully apply them and readers with a good understanding of basic control charting methodology will have no difficulty comprehending, or applying, any of the techniques contained in this 8.5 by 11 inch, two-volume set.
|
Description of Each Chapter
1. Introduction - the unrelenting need for reducing variation in all processes.
2. Review of Basic Statistics - a brief review of several fundamental statistical concepts: sample average and standard deviation; variable- and attribute-data control charts; estimating the process average and standard deviation; calculating capability indexes.
3. Overview of Variation-Reduction Strategies - the difference between sporadic and chronic causes of variation; the process improvement strategies of Juran, Deming, Taguchi, Six Sigma, and an introduction to the seven-step DOT*STAR strategy that is presented in the remainder of this book.
Step 1-Define the Problem
4. State the Problem: the formulation of a precise and clearly written problem statement helps everyone focus their energies on one specific concern.
5. Choose an Important Problem: this chapter shows how to prioritize quality concerns and identify those whose solution will most benefit the company. Tools include Pareto analysis, 3-D Pareto diagrams, weighted Pareto analysis, pie charts, and locating bottleneck operations.
6. Form a Variation-Reduction Team: once a specific problem is chosen, a team of the right subject experts can be assembled to tackle this concern. This chapter explains how to form effective teams, choose the most qualified members, properly locate the team, and how the team should operate.
Step 2-Observe the Process
7. Prepare for a Background Study: the newly formed team should flowchart the process, review existing historical data, then verify the accuracy and repeatability of the measurement system.
8. Collect, Record, and Analyze Process Data: this chapter presents numerous methods for gathering and evaluating new process data: check sheets, concentration diagrams, histograms, stem-and-leaf plots, run charts, and matrix diagrams, as well as several data-collection strategies.
9. Generate Clues with Multi-vari Charts: this technique is especially well suited for analyzing multiple sources of common-cause variation: within piece, piece to piece, time to time, and process stream to process stream.
10. Quantify Attribute Data: many processes in need of improvement generate attribute data. This chapter provides several procedures for transforming this type of data into measurements resembling variable data so more powerful techniques can be applied to analyze these measurements.
11. Component Swapping: this powerful search pattern helps isolate the component responsible for the majority of variation in performance between two large assemblies, e.g., engines, transmissions, or machines.
Step 3 - Think of Possible Causes of Variation
12. Generate a List of Potential Causes: utilizing the clues collected in Step 2, the team now thinks of what process variables or inputs fit these clues. Techniques for accomplishing this objective include 5Ws and 2Hs, five whys, brainstorming, and Crawford slip method.
13. Organize the Potential Causes: to better perceive any interrelationships among the suggested causes, team members should organize their ideas on a cause-and-effect diagram (several varieties of this technique are discussed), or arrange them on a force-field graph.
Step 4 - Select the Most Likely Cause
14. Analyze and Rank the Potential Causes: after thinking of many possible causes in Step 3, the team must rank them by determining how well each fits the clues from Step 2. Methods covered include multi-voting, nominal group technique, pair-wise comparisons, causes versus clues matrix, and decision making by consensus.
Step 5 - Test to Verify the Selected Cause
15. Basic Verification Techniques: once a likely cause is chosen in Step 4, the team must confirm it is really a major cause of process variation before attempting to implement a solution. If it isn't a major cause, the team's second choice must be tried. This iteration of select/test, select/test continues until a major cause is verified. This vital chapter explains how to: plan and conduct a verification test; confirm a shift in the process average, a reduction in the process standard deviation, or a reduction in the percentage of nonconforming parts with control charts (including special zone run rules).
16. Scatter Diagrams: in addition to confirming the relationship between the problem and the suspected cause, this graphical method can help determine a realistic tolerance for the cause. Also presented are multi-grams (for portraying the relationships between multiple variables) and isograms (for quantifying the degree of agreement between two measurement systems or two inspectors).
17. Randomizing: the statistical validity of many techniques often demands that parts be collected and/or measured in a random order. This chapter not only explains how to randomize, but also why randomization is needed.
18. Comparison Testing: a cause can be verified by measuring a suspected part feature on a small sample of "bad" parts and on a small sample of "good" parts. By simply ranking these measurements, a team can determine whether or not the tested feature is related to the problem under investigation.
19. Statistical Hypothesis Testing: this chapter covers hypothesis tests for verifying a reduction in the process standard deviation, a shift in the process average, and a reduction in the percentage of nonconforming parts. Tests are also provided for comparing two standard deviations, two averages, or the percentage nonconforming between two processes. Special "look-up" tables simplify the calculation of test values.
20. Analysis of Means: a graphical approach for comparing the performance among two or more processes, based on their standard deviations, averages, or percentages of nonconforming parts.
Step 6 - Act to Develop and Implement a Solution
21. Create and Analyze Potential Solutions: after a major cause of variation in confirmed in Step 5, the team must come up with a solution to remedy the problem. This chapter shows how team members can generate a number of alternative solutions, compare and evaluate them, then select the one they believe is most likely to succeed. Methods in this chapter include: effort/impact grid, pair-wise comparisons, plus-minus-indifferent (PMI) analysis, and the prioritization matrix technique.
22. Evaluate and Refine the Chosen Solution: when a tentative solution is selected, a trial run should be conducted to verify its effectiveness. Any difficulties experienced in this pilot study can be addressed by completing a solution FMEA. Installing a poka-yoke device can mistake proof a process so that the cause of the problem can never return.
23. Implement the Solution: a Gantt chart or an arrow diagram can help a team schedule and track the implementation of a solution. Work instructions should be modified and operators retrained to make sure these changes become a permanent part of the process.
24. Disband the Team: after a chronic problem has been successfully solved, the team should make a final presentation to upper management, preserve the valuable knowledge gained about the process, thank all members, and then officially disband itself since the team's assignment has been completed.
Step 7 - Review and Revise the Solution
25. Maintain and Improve the Solution: because all processes will change over time, the team's solution must be closely monitored to prevent a reoccurrence of the problem. Because control charts are designed to prevent changes in a process, several special charts are covered: the Group chart for monitoring multiple process streams; the 3-D chart for tracking processes that have within-part variation; modified limits for processes with tool wear. In addition to charts, the organization can maintain the team's gains via preventative maintenance, work instructions, and internal process audits. The concept of kaizen is introduced to demonstrate why everyone in the organization needs to participate in on-going process improvement.
26. Start a New Journey: continuous improvement is necessary to remain competitive in today's worldwide markets. Thus, having just completed the final step of the DOT*STAR strategy, the organization must return to Step 1 and begin another cycle of reducing process variation. Several tables of statistical constants are included.
This two-volume set of books was printed in the USA.
|
Pricing
Price per Book
Quantity
1 - 4
5 - 9
10 and over
|
(U.S. Dollars)
$139
$129
$119
|
Please add $6 postage and handling for each book ordered -- overseas orders must add $16 per book (please allow 2 weeks for delivery in the U.S., 6 weeks for overseas deliveries). Check, made out to IQI, or purchase order must accompany written orders. All checks must be in U.S. dollars, payable at a U.S. bank. We now accept VISA and MasterCard credit cards (call 262-375-8868 to order).
|
Industrial Problem Solving Booklet
by Davis Bothe, 42 pages, soft cover, $4.00
Over 95,000 copies currently in print.
Control charts are great for identifying the special causes of variation that result in a process going out of control. Unfortunately, when a process is in control but not capable, control charts aren't much help in reducing process variation due to common causes. For this task, you need other statistical techniques, several which are explained in this pocket-sized booklet (3.3 by 5.3 inches). However, this booklet is not just a listing of techniques, but more importantly, it explains a proven game plan for successfully applying them in a step-by-step procedure. We call this powerful method the DOT*STAR process-improvement strategy (DOT*STAR is an acronym created from the first letter of the name for each of the seven steps in this strategy, as shown below). We developed this strategy for process improvement in the early 1980s, several years before Motorola came up with its similar DMAIC approach.
|
Steps of IQI's DOT*STAR Strategy
D - Define the Problem
O - Observe the Process
T - Think of Potential Causes
S - Select the Most Likely
T - Test to Verify the Cause
A - Act to Implement a Solution
R - Review and Revise the Solution
To illustrate the power and ease of use of this remarkable approach, the resolution of an actual industrial quality problem in a small shop is followed through the above seven steps, beginning with defining the problem and ending with reviewing the successfully implemented solution. Because this strategy is becoming so popular, we have also created a two-day Statistical Problem Solving seminar around it as well as written a two-volume book called Reducing Process Variation, which is now used in many six sigma black belt training programs.
We first developed the DOT*STAR strategy in the early 1980s and many companies have patterned their own process-improvement strategy on ours. In fact, there are presently over 95,000 copies of this handy booklet in use around the world. This booklet was printed in the USA.
|
Pricing
Only $4.00 per copy (volume discounts are available). Please add $0.50 postage and handling for each book ordered, overseas orders must add $1.00 per book (allow 2 weeks for delivery in the U.S., 6 weeks for overseas deliveries). Check, made out to IQI, or purchase order must accompany written orders. All checks must be in U.S. dollars, payable at a U.S. bank. We now accept VISA and MasterCard credit cards (please call 262-375-8868 to order). We have a few copies written in Spanish left. Call for more information.
|
US Army AMCCOM Document - SPC for Short Production Runs
46 pages, $14.95
Because of our work over the years to develop and promote the use of short-run SPC methods, the U.S. Army commissioned IQI in 1988 to write a document (number DAAA08 88 M 7649) about this topic that they could send to all their defense contractors as part of their quality management system requirements.
Written for AMCCOM, the Army's procurement agency for armaments, munitions, and chemicals, this 61-page booklet includes our special short-run charts for variable and attribute data (see list below). There is also a brief section on capability studies and mention of the 3-D and Group control charts as well.
Table of Contents
Nominal X-bar, R
Target X-bar, R
Short Run X-bar, R
Standardized X-bar, S
Short Run IX & MR
Short Run MA & MR
Short Run c, u, np, p
|
Pricing
You may order this spiral-bound document (8.5 by 11 inches) by calling 262-375-8868. Only $14.95 per copy. Please add $2.05 postage and handling for each book ordered, overseas orders must add $6.05 per book (allow 2 weeks for delivery in the U.S., 6 weeks for overseas deliveries). Check, made out to IQI, or purchase order must accompany written orders. All checks must be in U.S. dollars, payable at a U.S. bank. We now accept VISA and MasterCard credit cards. This document was printed in the USA.
|
SPC for Short Production Runs Reference Handbook
by Davis Bothe, 63 pages, $19.95
To consolidate the numerous methods that we developed for applying control charts to high-mix/low-volume manufacturing, we first published this reference handbook in 1991. Written by Davis Bothe, a recognized leading expert in the field of short-run SPC, this manual begins by listing the three main reasons why traditional control charts are not effective in short-run situations, such as job shops and companies employing lean manufacturing.
The main portion of this manual introduces 17 new control charts for monitoring low-volume production (all of which, by the way, are covered in our Short Run SPC seminar). Control chart formulas are presented along with an explanation of how to properly apply and interpret these unique and powerful charts. A fully worked-out example of each type of chart is prominently displayed so readers can easily follow all necessary calculations.
Table of Contents
Nominal X-bar, R
Target X-bar, R
Short Run X-bar, R
Short Run X-bar, S
Standardized X-bar, S
Nominal IX & MR
Target IX & MR
Short Run IX & MR
Nominal MA & MR
Target MA & MR
Short Run MA & MR
Short Run c, u, np, p
In addition, two application-decision flow charts are included to help you select the proper short-run chart for any situation, whether dealing with variable or attribute type data. Extra sections describe how to correctly interpret these charts for both part number control and process control, as well as how to determine appropriate target values for the process output parameters.
In its ninth printing since being originally published in 1991, this 64-page, spiral-bound handbook (8.5 by 11 inches) includes several statistical tables of control limits constants and a glossary of SPC terminology. This valuable reference should be required reading for every quality engineer, black belt, and SPC facilitator. If you work for a defense contractor, you may be interested in a document that the U.S. Army commissioned us to write for their defense contractors on how to apply SPC to short runs.
|
Pricing
This reference handbook is just $19.95 per copy. Please add $2.05 postage and handling for each book ordered, overseas orders must add $5.05 per book (allow 2 weeks for delivery in the U.S., 6 weeks for overseas deliveries). Check, made out to IQI, or purchase order must accompany written orders. All checks must be in U.S. dollars, payable at a U.S. bank. We now accept VISA and MasterCard credit cards. To order, call 262-375-8868. This handbook was printed in the USA.
|
Using Normal Probability Paper to Estimate Process Capability
by Davis Bothe, 72 pages, $14.95
One of our more popular workbooks explains how normal probability paper (NOPP) can be used to easily estimate the Cp and Cpk indices of process capability for both normal and non-normal process output distributions. This 72-page booklet:
- Reviews the definition of process capability
- Demonstrates why process control is required before estimating capability
- Develops formulas for Cp, Zmin, and Cpk
- Illustrates how to plot data on NOPP and interpret the results
- Describes how to identify non-normal distributions
- Tells how to estimate process parameters from NOPP
- Shows how percentages nonconforming and ppm are estimated
- Explains how to estimate capability for both normal and non-normal distributions
- Incorporates many real-life examples
- Contains several exercises (with answers provided)
Included with this spiral-bound booklet (8.5 by 11 inches) are five sheets of our newly designed Six-Sigma Capability Analysis Worksheet, which is the only NOPP available that extends from -6 sigma to +6 sigma. Containing scales for percentage nonconforming, ppm values, Z scores, as well as Cpk indices, this oversized worksheet (17 by 22 inches) greatly simplifies the estimation, recording, and analysis of capability measures. Our NOPP worksheet can be purchased separately. Both this booklet and the NOPP worksheet are printed in the USA.
|
Pricing
This valuable workbook that every quality engineer, statistical engineer, and black belt should own is only $14.95 per copy. Please add $2.05 postage and handling for each book ordered, overseas orders must add $5.05 per book (allow 2 weeks for delivery in the U.S., 6 weeks for overseas deliveries). Check, made out to IQI, or purchase order must accompany written orders. All checks must be in U.S. dollars, payable at a U.S. bank. We now accept VISA and MasterCard credit cards. To order, call 262-375-8868.
|
Specialized Charting Forms
In order to properly analyze process data, you need the right type of chart paper. We provided quite a variety of forms at minimum cost that should handle all your special charting needs, especially for short-run SPC. After purchasing the first pad, you may use one of the sheets as a master to make additional copies. However, these copies may be used at only the facility that originally bought the chart paper.
|
CPF101 Chart paper for traditional attribute charts. Form for the traditional np, p, ,c and u charts. 11 by 17 inches
|
CPF103Chart paper for traditional group X-bar, R charts. Form for handling multiple process streams (cavities, spindles) on one chart. Can be used with either the X-bar, R or IX & MR chart. 11 by 17 inches.
|
CPF201 Chart paper for short-run attribute charts. Form for the short-run np, p, c and u charts. 11 by 17 inches.
|
CPF202 Chart paper for short-run X-bar, R-chart. Form for either the short-run X-bar, R or short-run IX & MR chart. 11 by 17 inches.
|
CPF203 Chart paper for group short-run X-bar, R chart. Form for grouping several process streams on the same chart. Works for either the short-run X-bar, R or short-run IX & MR chart. 11 by 17 inches.
|
CPF205 Chart paper for nominal/target chart. Form for the nominal X-bar, R or IX & MR charts as well as the target X-bar, R or IX & MR charts. 11 by 17 inches.
|
Pricing
All control charting paper comes in pads, with 10 copies to a pad. Pads cost $4.00 each, plus $1.00 postage and handling for U.S. shipments, $5.00 for overseas shipments. Order by form number. All our forms are printed in the USA.
|
NOPP Six-Sigma Capability Analysis Worksheet. The only normal probability paper available that extends from -6 sigma to +6 sigma. It contains scales for percentage nonconforming, ppm values, Z scores, as well as for the Cpl and Cpu indices. Printed in eye-saving green, this oversized worksheet (17 by 22 inches, folds to 8.5 by 11 inches) greatly simplifies the estimation, recording, and analysis of capability measures. If you are not familiar with normal probability paper, you can learn all about it with our special booklet, Using Normal Probability Paper to Estimate Process Capability.
|
Pricing
$5.00 for 10 sheets, plus $1.00 postage and handling for U.S. shipments, $5.00 for overseas shipments. Order by form number. All our forms are printed in the USA.
|
|
|
