An Integrated Performance Modeling System

2004 ◽  
Author(s):  
David Kazmer ◽  
Liang Zhu
Keyword(s):  
Quality Control ◽  
Performance Modeling ◽  
Specification Limits ◽  
Performance Variables ◽  
Historical View ◽  
Decision Variables ◽  
Current Value ◽  
Integrated Performance ◽  
Control Limits ◽  
Function Matrix

An integrated performance modeling system is presented for use in general decision making problems including engineering design, manufacturing process and quality control, and other applications. The system relies on a function matrix that relates decision variables to performance variables. The system utilizes both global and local linearization of non-linear functions, after which the Extensive Simplex Method is used to derive the set of all feasible decisions based upon the specification limits for the performance variables and the control limits on the decision variables. Beyond current Six Sigma best practices, the described system explicitly considers both modeling uncertainty and uncontrolled variation. The specification limits may be automatically tightened by the confidence intervals and variation limits to ensure feasibility to a desired level of confidence and robustness. Three sets of feasible decisions are established including 1) the global feasible set that establishes the extreme limits of feasibility by allowing all the decision variables to vary simultaneously within their range of the control limits, 2) the local feasibility, which shows the immediate feasibility for each decision variable holding other decision variables at their current value, and 3) the controllable feasibility for each performance variable holding other performance variables at their current value. The system provides a perspective view of 1) the function matrix, 2) a historical view of the decision variables which may be used in a manner similar to statistical process control X-Bar charts, 3) a historical view of the performance variables which may be used in a manner similar to statistical quality control charts, 4) a set of decision windows showing the joint feasibility of all pairs of decision variables, which may be used in a manner similar to process windows, and 5) a set of performance windows showing the joint feasibility of all pairs of performance variables, which may be used in a manner similar to Pareto Optimal graphs. An example is provided for a beam design model with four decision variables and three performance variables.

Qualitative Reasoning for Decision Synthesis

2001 ◽  
Author(s):  
David Kazmer ◽  
Liang Zhu
Keyword(s):  
Qualitative Reasoning ◽  
Relationship Matrix ◽  
Engineering Systems ◽  
Qualitative Model ◽  
Specification Limits ◽  
2Nd Generation ◽  
Reusable Launch Vehicle ◽  
Decision Variables ◽  
Sheet Extrusion ◽  
Control Limits

Abstract A qualitative reasoning approach is presented for decision support. This approach is initiated with the generation and normalization of a qualitative model including relationship matrix, importance weightings, control limits for decision variables, and specification limits for performance attributes. An extensive Simplex method is then utilized for mapping the global feasibility of the decision problem. Finally, the approach interprets and simplifies the results from the multi-dimensional feasibility space back to the qualitative model. The paper also presents application of the approach to process tuning of multilayer sheet extrusion and concept development of a 2nd generation reusable launch vehicle to orbit. The results indicate that the developed approach is a viable alternative to currently practiced decision analysis methods. Specifically, the approach uses: 1) tightened specification limits rather than a weighted multi-attribute objective relationship, 2) determines global system feasibility from active constraints rather than local parametric optimization, and 3) establishes correlations based on dynamic Pareto-optimal frontiers rather than manual estimations. While the approach is potentially useful, further research is required to extend the methods to non-linear, stochastic, and uncharacterized engineering systems.

scholarly journals Impact of Variations in Test Method Parameters onIn VitroActivity of Surotomycin against Clostridium difficile and Surotomycin Quality Control Limits for Broth Microdilution and Agar Dilution Susceptibility Testing

2015 ◽  
Vol 54 (3) ◽  
pp. 749-753 ◽  
Author(s):  
Maria M. Traczewski ◽  
Jennifer Deane ◽  
Daniel Sahm ◽  
Steven D. Brown ◽  
Laurent Chesnel
Keyword(s):  
Quality Control ◽  
Clostridium Difficile ◽  
Calcium Concentration ◽  
Susceptibility Testing ◽  
Test Method ◽  
Test Parameter ◽  
Content Type ◽  
Parameter Variations ◽  
Agar Dilution ◽  
Control Limits

Test parameter variations were evaluated for their effects on surotomycin MICs. Calcium concentration was the only variable that influenced MICs; therefore, 50 μg/ml (standard for lipopeptide testing) is recommended. Quality control ranges forClostridium difficile(0.12 to 1 μg/ml) andEggerthella lenta(broth, 1 to 4 μg/ml; agar, 1 to 8 μg/ml) were approved by the Clinical and Laboratory Standards Institute based on these data.

scholarly journals Combining Capability Indices and Control Charts in the Process and Analytical Method Control Strategy

2020 ◽  
Author(s):  
Alexis Oliva ◽  
Matías Llabrés
Keyword(s):  
Control Strategy ◽  
Analytical Method ◽  
Control Charts ◽  
Process Capability ◽  
Real Data ◽  
Process Capability Indices ◽  
Specification Limits ◽  
Capability Indices ◽  
And Control ◽  
Control Limits

Different control charts in combination with the process capability indices, Cp, Cpm and Cpk, as part of the control strategy, were evaluated, since both are key elements in determining whether the method or process is reliable for its purpose. All these aspects were analyzed using real data from unitary processes and analytical methods. The traditional x-chart and moving range chart confirmed both analytical method and process are in control and stable and therefore, the process capability indices can be computed. We applied different criteria to establish the specification limits (i.e., analyst/customer requirements) for fixed method or process performance (i.e., process or method requirements). The unitary process does not satisfy the minimum capability requirements for Cp and Cpk indices when the specification limit and control limits are equal in breath. Therefore, the process needs to be revised; especially, a greater control in the process variation is necessary. For the analytical method, the Cpm and Cpk indices were computed. The obtained results were similar in both cases. For example, if the specification limits are set at ±3% of the target value, the method is considered “satisfactory” (1.22<Cpm<1.50) and no further stringent precision control is required.

Simulation of human judgement in a robot-based adjustment system

Robotica ◽  
1984 ◽  
Vol 2 (4) ◽  
pp. 209-214 ◽  
Author(s):  
Fazel Naghdy ◽  
John Billingsley ◽  
David Harrison
Keyword(s):  
Decision Making ◽  
Quality Control ◽  
Automatic System ◽  
Computer Modelling ◽  
Performance Variables ◽  
Adjustment Procedure ◽  
And Performance ◽  
Adjustment System

SUMMARYA robot-based automatic system for adjusting energy regulators in electric cookers is described in this paper. It is claimed that this system improves the quality of the regulators and increases productivity. First, the operator's intuitive judgement and decision-making are simulated on a microcomputer; the structure and performance variables of the regulator are then described. A discussion of computer modelling of the regulator then follows, leading to the development of an algorithm for the adjustment procedure and overall strategy of the system. Experiments on 2,000 regulators showed that this automated operation was superior to the manual procedure as regards consistency and accuracy. This technique based on a robot may be applied to quality control and manufacture of a variety of similar products.

Performance of a Turbine Driven by a Pulsed Detonation Combustor

2011 ◽  
Author(s):  
Kurt P. Rouser ◽  
Paul I. King ◽  
Frederick R. Schauer ◽  
Rolf Sondergaard ◽  
John L. Hoke
Keyword(s):  
Reverse Flow ◽  
Specific Work ◽  
Time Resolved ◽  
Performance Variables ◽  
Pulsed Detonation ◽  
Fill Fraction ◽  
Pressure Gain Combustion ◽  
Time Histories ◽  
Exit Temperature ◽  
Integrated Performance

There is longstanding government and industry interest in pressure-gain combustion for use in Brayton cycle-based engines. Theoretically, pressure-gain combustion allows heat addition with reduced entropy loss. The pulsed detonation combustor (PDC) is a device that can provide such pressure-gain combustion and possibly replace the typical steady deflagration combustor. The PDC is inherently unsteady, however, and comparisons with steady deflagration combustors must be based upon time-integrated performance variables. In this study, the radial turbine of a Garrett automotive turbocharger was coupled directly to and driven, full admission, by a hydrogen-fueled PDC fueled. Data included pulsed-cycle time histories of turbine inlet and exit temperature, pressure, velocity, mass flow, and enthalpy. The unsteady inlet flowfield showed momentary reverse flow, and thus unsteady accumulation and expulsion of mass and enthalpy within the device. The coupled turbine-driven compressor provided a time-resolved measure of turbine power. Duty cycle increased with PDC frequency. Power and cycle-average specific work increased with PDC frequency and fill fraction.

Specification-Based Modified Control Limits in Quality Control of Trace Chemical Analyses

1992 ◽  
Vol 75 (1) ◽  
pp. 39-45
Author(s):  
C L Grant ◽  
I E Mcgee ◽  
T F Jenkins ◽  
M H Stutz
Keyword(s):  
Quality Control ◽  
Data Quality ◽  
Chemical Analyses ◽  
Percent Recovery ◽  
Total Variability ◽  
Standard Deviations ◽  
Control Limits

Abstract Shewhart X and R charts were used to maintain and validate data quality of percent recovery estimates for 8 analytes determined by 4 procedures used routinely in 4 commercial laboratories over a 2-year period. However, because range (R) estimates of uncertainty did not Include lot-to-lot calibration variability, approximately 24% of the lots were "out-of-control." We extracted pooled standard deviations for So (repeatability within lot), SL (calibration variability), and SR (reproducibility), which represents the total variability. Values of So and SL were generally similar In size although there were some substantial differences between analytes and between laboratories for a given analyte. When control limits were based on reproducibility rather than repeatability, only about 6% of the lots were "out-of-control." However, these limits are less convenient to compute at the bench, wlthln-lot precision estimates are still required, and there Is still no Information on data acceptability. Capability estimates from the grand mean ±3 SR were surprisingly consistent for the 8 analytes. These values coupled with data quality objectives suggested the 82-115% range as the specifications for acceptable individual recoveries. A combination of repeatability limits plus modified limits anchored to specifications retains the simplicity of range computations while offering substantial administrative advantages. Examples are given to illustrate these points.

Development of Specification Limits for Asphalt Pavements Based on Quality Control and Quality Assurance Data

2011 ◽  
Vol 39 (6) ◽  
pp. 103612
Author(s):  
M. R. Mitchell ◽  
R. E. Link ◽  
Jian-Shiuh Chen ◽  
Min-Chih Liao ◽  
Ching-Hsiung Wang
Keyword(s):  
Quality Control ◽  
Quality Assurance ◽  
Asphalt Pavements ◽  
Specification Limits

Quality control limits for microdilution susceptibility tests with aztreonam, imipenem, ceftriaxone, ceftazidime, ceftizoxime, cefuroxime, and cefonicid

1987 ◽  
Vol 7 (1) ◽  
pp. 83-87 ◽  
Author(s):  
Arthur L. Barry ◽  
Thomas L. Gavan ◽  
Ronald N. Jones ◽  
Leona W. Ayers ◽  
Peter C. Fuchs ◽  
...  
Keyword(s):  
Quality Control ◽  
Susceptibility Tests ◽  
Control Limits
Sign in / Sign up

Export Citation Format

Share Document