Tolerance analysis and synthesis plays a vital role in the success of a product design because it directly affects product quality and manufacturing cost. It also affects manufacturing process selection and planning. This research provides a review of several commonly used assembly tolerance analysis models and evaluation of their limitations....
The economic aspects of quality control have received wide concern since its developmental stages, however, they have not been sufficiently explored. Moreover, as the need for complex products of high precision and reliability increases, most industrial firms have experienced some difficulties in meeting that need at reasonable costs with their...
A dynamic approach to the Bayesian theory of sampling inspection
by attributes for the single sampling case is presented. A model is
developed which assumes a sequence of lots of equal known size and
lots generated by a process operating in a random manner. The model
also assumes constant associated...
An analysis and modeling method of the diagnostic characteristics of a mechanical or electromechanical system is presented. Diagnosability analysis is especially relevant given the complexities and functional interdependencies of modern-day systems, since improvements in diagnosability can lead to a reduction of a system's life-cycle costs. The diagnosis process of a...
Tolerance analysis and synthesis plays a vital role in the success of a product design because it directly affects product quality and manufacturing cost. It also affects manufacturing process selection and planning. This research provides a review of several commonly used assembly tolerance analysis models and evaluation of their limitations....
Radiation therapy is used in approximately half of all cancer treatments. The rapid advances in radiation therapy have led to techniques that are much more complex and therefore must be more carefully assessed for safety and efficacy. Accurate quality assurance methods must be implemented to provide patient safety and confidence...
In the highly competitive animal protein market, seafood faces increasing pressure to improve and standardize product quality. While there is general consensus that quality can be improved for many seafood products, there is little agreement on the types and levels of characteristics that should define "quality." This is a fundamental...
In production processes, there are two types of
variations that affect production quality - - variations
produced by chance causes and variations produced by
assignable causes. One of the main instruments in quality
control used to control quality by distinguishing between
variations produced by chance causes and a real process...
When the nonconformities are independent, a multivariate control chart for nonconformities called a demerit control chart using a distribution approximation technique called an Edgeworth Expansion, is proposed. For a demerit control chart, an exact control limit can be obtained in special cases, but not in general. A proposed demerit control...
Networks of distributed, remote sensors are providing ecological scientists with a view of our environment that is unprecedented in detail. However, these networks are subject to harsh conditions, which lead to malfunctions in individual sensors and failures in network communications. This behavior manifests as corrupt or missing measurements in the...
Statistical Process Control techniques have been successfully
implemented in the mechanical fabrication and chemical manufacturing
industries. The techniques consist of the application of statistical
theory in conjunction with quality control procedures. To date the
Forest Products industry has yet to apply these techniques toward lumber
drying. This thesis focuses on...
Quality Function Deployment (QFD) is a product development process that
assures the needs and desires of the customer are heard and heeded during the
design, development and production of a product. Though it has been used
successfully in other industries, only a few companies in the U. S. Engineering
and...
The purpose of this study was to derive a set of sampling plans
to be used by the Western Wood Products Association for the reinspection of shipped lumber. Reinspection of a shipment of lumber
occurs when a claim of grade is made by the buyer.
Each sampling plan is derived...
The purpose of this study was to investigate an application of
statistical concepts to quality control of highway construction. The
application was presented qualitatively and demonstrated quantitatively
by an investigation of asphalt content in asphalt concrete.
For the example, an Oregon State Highway Project was
sampled and tested. The average...
Control charts are designed to monitor population parameters. Selection of a
control chart sampling plan involves determination of the frequency of samples, size
of each sample, and critical values to determine when the system is sending an out-of-control signal. Since the main use of control charts is in industry, a...
Prioritization techniques are used to schedule test cases to execute in a specific order to maximize some objective function. There are a variety of possible objective functions, such as a function that measures how quickly faults can be detected within the testing process, or a function that measures how fast...
Test case prioritization techniques schedule test cases for regression testing in an order that increases their ability to meet some performance goal. One performance goal, rate of fault detection, measures how quickly faults are detected within the testing process. The APFD metric had been proposed for measuring the rate of...
Product quality control is the back bone for an efficient process control system. By monitoring the size of the board cut in a sawmill, performance of the production system can be controlled. Feedback from the quality control system is used to evaluate the status of the production system and also...
Continuous Improvement (CI) is an integral part of hospital administration. This study examined the relationship between five CI variables against six hospital criterion measures of, wait times to prepare a room, patient costs per day, waiting time for lab results, reportable errors, patient satisfaction, and employee satisfaction. The research was...
Published August 1940. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published 1914. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Flowcharts graphically represent the steps in creating a product
or service. The process of creating a chart is often beneficial
because personnel may be unaware of all the “nitty-gritty” details
involved in producing the product. Also, people often are surprised
to learn of the differences between the ideal process flow...
Part 1 in this series introduced the reader to Statistical Process Control, and Part 2 provided an overview of how and why SPC works.
Part 3 begins the step-by-step process of building the practical skills
necessary for hands-on implementation of SPC. This report discusses Pareto analysis, a tool we can...
The goal for Part 2 is to build management understanding and
confidence in SPC as a profit-making tool. It is unreasonable to expect
managers to commit to and support SPC training and implementation
if they do not understand what SPC is and how and why it works. This
publication discusses...
The objective of this series is to help improve the competitiveness of
Oregon’s wood products manufacturers. This can be achieved by fostering a companywide focus on and dedication to continuous quality improvement.
W. Edwards Deming (1982) described the “chain reaction of quality.”
1. Quality is improved.
2. Costs decrease due...
In Part 5, we now turn our attention to cause-and-effect diagrams (CE diagrams). CE diagrams are designed to help quality improvement teams identify the root causes of problems.
Current lathe technology, smaller diameter logs, smaller core diameters, and
the sale of higher grade veneer for use in engineered wood products are all factors
contributing to plywood manufacturers using rougher veneer with different lathe
check characteristics. When rough veneer is encountered, plywood manufacturers
typically increase the adhesive spread rate...
This publication focuses on how design of experiments can help companies solve problems in manufacturing. Part of the Performance Excellence in the Wood Products Industry series.
Pacific whiting, with a maximum sustainable yield between 150,000 and 250,000 metric tons, is the largest stock of fish found off Oregon. The majority of the fish are processed into surimi. Hundreds of variables could potentially affect surimi quality (gel strength). Alternative harvesting and processing input combinations, as well as...
The principal objective of this study was to compare the results of a proposed method based upon the response surface model to the Taguchi method. To modify the
Taguchi method, the proposed model was developed to encompass the following
objectives. The first, with the exception of the Taguchi inner array,...
Tolerance analysis is a major link between design and
manufacturing. An assembly or a part should be designed
based on its functions, manufacturing processes, desired
product quality, and manufacturing cost. Assembly tolerance
analysis performed at the design stage can reduce potential
manufacturing and assembly problems. Several commonly used
assembly tolerance...
This study explored the influence of motivations on the volunteer experience. The relationship among motivations. volunteer satisfaction, acceptance and support of the organizational goals, and outcomes of success in the volunteer role (pattern of participation and ombudsman effectiveness) were explored using Multiple Linear Regression analyses. Motivational Systems Theory (Ford, 1992)...
Statistics and Metrics Generator (SMG), is a software tool that gathers, stores and reports
performance and execution metrics for a web-based software installation process. The
purpose of this project was to develop a software utility that provides feedback about software
download and installation process efficiency. A web-based software installation is...
This thesis investigates the feasibility of implementing a
real time quality control program into a data stream of
hydrometeorlogical data. The vast array of data used in the
forecasting of river levels and avalanches calls for a point of entry
quality control method that is both efficient from a
communications...
Whole oysters were processed under a series of pressures from 30,000 to 45,000 psi at different holding times (0, 1, and 2 min) and then stored at <4°C, for 27 d. During the shelf-life study, the quality of oysters was determined by measuring pH, moisture content, and microbial counts including...
In recent years, the forest products industry has been
forced to cope with a supply of raw material that is
declining in both quality and quantity. In addition, log
prices are escalating rapidly. Because log costs may
represent as much as 90 percent of the overall production
costs of lumber...
This thesis describes a Systemic Vulnerability Identification and Remediation (SVIR) methodology that identifies human fallibilities and errors in complex technical processes, and recommends remediations for the errors, based on human factors principles and guidelines. The objectives of the research described in the thesis are the development of the methodology and...
Citizen Science is a paradigm in which volunteers from the general public participate in scientific studies, often by performing data collection. This paradigm is especially useful if the scope of the study is too broad to be performed by a limited number of trained scientists. Although citizen scientists can contribute...
Least cost formulations for surimi seafood were studied
by linear programming (LP) and nonlinear programming (NLP).
The effects of water and starches on functional properties of
Alaska pollock and Pacific whiting surimi gels were
investigated. Six starches (modified potato starch, potato
starch, modified wheat starch, wheat starch, modified waxy corn...
Training is a key business process used to increase the skills and knowledge of employees in an effort to improve overall performance. Evaluation of the effectiveness and efficiency of training processes is necessary to ensure time, money, and resources are used to provide the most benefit possible. This investigation is...
The distortions of input voltage and current waveforms generated by switch mode power supply (SMPS) operation are a major cause of concern in the power quality performance of commercial office buildings. These distortions are usually evaluated by performing a site survey of the building. In this thesis, a power quality...
With the increased attention on high efficiency and controllability of industrial processes, as well as reduced weight, volume and cost of consumer products, the applications of nonlinear power electronic converters such as adjustable speed drives (ASDs) are showing a rapid rise. Power Quality (PQ) is becoming an increasing concern with...