Modified Nominal/Target Control Charts—A Case Study in Supplier Development
S. K. Vermani, The Boeing Company
This article describes a technique to modify nominal/target control charts that does not increase the length of control charts regardless of the number of quality characteristics. The article focuses on Supplier Quality Management (SQM), a part of The Boeing Company, which has been working with the supplier community to help them reduce costs without giving up profits.
Their strategy involves using statistical process control (SPC), a tool for controlling the processes of manufacturing complex parts. However, if SPC is deployed for process control of a complex part with a large number of quality characteristics, the number of control charts and capability indices becomes very large. Also, short-run charts are prone to misinterpretation, particularly if the number of quality characteristics exceeds seven. To assess process capability of a quality characteristic to meet bilateral tolerances, a set of four capability indices is required. A complex part with many quality characteristics could have four times as many capability indices. Keeping track of a large number of capability indices is burdensome.
The author describes a methodology where the length of a short-run control chart does not increase with the number of quality characteristics. In the new methodology, all quality characteristics of all parts in the subgroup are combined to make a larger subgroup, which minimizes the number of points per chart and eliminates the risk of misinterpretation of the state of process. Additionally, if the design tolerances differ only in the nominal for each quality characteristic but the plus or minus part of the tolerances is the same for all quality characteristics, then the number of capability indices can be reduced to just one set of four indices, regardless of the number of quality characteristics in the part.
Environmental Uncertainty, Strategic Orientation, and Quality Management: A Contingency Model
Naceur Jabnoun, Azaddin Khalifah, and Attahir Yusuf, University of Sharjah
Although quality management practices have been implemented by many organizations all over the world, such implementations have often failed. This failure rate is largely attributed to the lack of integration between quality management practices, business strategy, and environmental uncertainty.
This article is designed to explore the relationship between levels of environmental uncertainty, specific strategic orientations, and quality approaches, and proposes a fit model that should increase the chances of firm performance. The three quality approaches addressed in this model are quality assurance, total quality management (TQM), and total quality learning (TQL). The Miles and Snow model is used as the strategic orientation typology. They classify firms by their adaptive decision patterns into the following:
- Prospectors: Focus on product innovation and market opportunities.
- Defenders: Search for market stability and offer and seek to protect a limited product line for a narrow segment of the potential market.
- Analyzers: Hybrid firms, which combine characteristics of prospectors and defenders.
- Reactors: Simply react to environmental change and make adjustments only when forced to do so.
Relating the quality approaches to the adaptive decision patterns of Miles and Snow, the authors easily detect a match between the defenders and quality assurance. The main objective of defenders is to secure a stable niche in the market, and quality assurance aims at achieving conformance. And, both defenders and quality assurance are internally focused.
The prospectors find common ground with TQL. Prospectors want to find and exploit new products and markets, while TQL looks for new pools of customers, and new customers’ needs. Both prospectors and TQL are externally focused.
TQM seems to match analyzers. Analyzers want to match new ventures to the present shape of business, while TQM seeks to meet customer expectations. Both analyzers and TQM focus on the process and the people who produce the product. Both are concerned with internal and external environments.
A Hands-On Application for Teaching Design for the Environment (DfE) Principles
Thomas F. Gattiker, Miami University
Design for the environment (DfE) is growing in importance. Traditionally, companies have considered their product’s environmental impact after the design phase. By contrast, DfE means considering a product’s environmental impact during product design. Considerations may include production processes that will be used, remanufacture, and so on.
Not surprisingly, DfE is showing up in college and graduate school curriculums, often as part of the overall quality function deployment framework. The application described in this article is appropriate for the traditional university classroom or possibly in a professional training context.
This article describes a highly participative and hands-on approach for teaching (DfE). By providing students with the opportunity to brainstorm about a particular product, they are able to discover DfE principles for themselves. The exercise presented in this article involves comparing a traditional videocassette with the G-zero videocassette. Teams of students are asked to disassemble a traditional videocassette and suggest ways to reduce its environmental footprint. They are then introduced to a newer type of videocassette, the G-zero, which is fully compatible with the traditional videocassette player, but has a much smaller environmental impact.
The cassette demonstrates that companies often must choose among different strategies for minimizing environmental impact. Once students understand the end-of-life strategy that was chosen, the instructor can begin to explain the ways in which the strategy can be designed into a product. The instructor can also walk students through some of the less obvious design features and explain the thinking behind the design. In addition to teaching DfE, this exercise can be used to introduce the notion of design skill as a source of competitive advantage.
Empirically Testing Some Main User-Related Factors for Systems Development Quality
Tor Guimaraes, Tennessee Technological University, and D. Sandy Staples and James D. McKeen, Queen’s University
The importance of user-related factors to system success has long been recognized by researchers. The study that is the focus of this article attempts to test the importance of these variables as determinants of system quality. It brings together into a more cohesive model some user-related variables that previously had only been studied separately by different authors. These include:
- User participation
- User expertise
- User/developer communication
- User training
- User influence
- User conflict
Given the variables being studied, the authors’ sample is focused on application systems developed by information systems professionals for a definable set of business users within an organization. Questionnaires were sent out, and the final sample size was 228.
Data from these 228 systems have been used to test proposed relationships between the independent variables and system quality.
Based on the results, the following of the authors’ hypotheses were accepted at the significance level or better:
- H1: User participation is directly related to system quality.
- H2: User expertise is directly related to system quality.
- H4: User training is directly related to system quality.
The authors’ other three hypotheses were not accepted. These included:
- H3: User-developer communication is directly related to system quality.
- H5: User influence is directly related to system quality.
- H6: User conflict is inversely related to system quality.
The results of this study indicate the importance of user participation in the system development process, user training, and user experience. The other variables—user/developer communication, user influence, and user conflict—seem to have no significant direct relationships with system quality.
