Geometrical Inspection Point Reduction Based on Combined Cluster and Sensitivity Analysis

Manufacturing ◽  
2003 ◽  
Author(s):  
Johan S. Carlson ◽  
Rikard So¨derberg ◽  
Lars Lindkvist
Keyword(s):  
Cluster Analysis ◽  
Computer Simulations ◽  
Small Subset ◽  
Industrial Case Study ◽  
Point Reduction ◽  
Minimum Number ◽  
Product And Process ◽  
Assurance Process ◽  
Inspection Data

Analyzing inspection data is an important activity in the geometry assurance process, which provides vital information about product and process performance. Since inspection is related to a significant cost, it is desirable with an intelligent inspection preparation where the motive is to gather as much information as possible about the product and the process with a minimum number of inspection points. In many situations, a large number of inspection points are used despite the fact that only a small subset of points is needed. The reason for this redundancy is that most systems have only a few principal causes affecting groups of variables. In this paper, we use methods of cluster analysis to find these natural groupings of inspection points and to select one representing point from each cluster. Furthermore, if the relationship between some of the process parameters and inspection points are known from experiments or from computer simulations, then the cluster analysis is combined with sensitivity-based reduction. In this way, an efficient reduced inspection plan is built up. The practical relevance of the proposed methodology for reduction is verified on an industrial case study and by computer simulations.

A pragmatic approach to interactive assembly sequence evaluation

2003 ◽  
Vol 217 (4) ◽  
pp. 541-550 ◽  
Author(s):  
C J Barnes ◽  
G E M Jared ◽  
K G Swift
Keyword(s):  
Relevant Literature ◽  
Stability Index ◽  
Design System ◽  
Assembly Planning ◽  
Assembly Sequence ◽  
Industrial Case Study ◽  
Assembly Sequences ◽  
Product And Process ◽  
Difficulty Index

An assembly-oriented design system has been developed which includes several analysis tools to improve product assemblability during product development. One of these tools supports the parallel development of the product design and the assembly sequence, thus exploiting the benefits of concurrent consideration of product and process. However, this approach requires some method for evaluating the sequence against requirements. Previous work on assembly sequence evaluation has concentrated on identifying the best from a set of ranked alternatives. When a single sequence is constructed, as with this tool, another method is needed. This paper reports the development of this novel methodology for evaluating individual assembly sequences. A review of the relevant literature has found several measures for identifying good assembly sequences from a ranked list and the fundamental sequence attributes extrapolated and aggregated. This leads to the proposal of four new indices: insertion index, stability index, difficulty index and complexity index. A large number of assembly sequences have been analysed to define limiting values for the indices such that they can quantify the potential of an incomplete sequence resulting in a satisfactory solution. The application of these indices in concurrent design and assembly planning is illustrated through an industrial case study.

scholarly journals Externalizing tacit overview knowledge: A model-based approach to supporting design teams

2007 ◽  
Vol 21 (3) ◽  
pp. 227-242 ◽  
Author(s):  
Tomás Flanagan ◽  
Claudia Eckert ◽  
P. John Clarkson
Keyword(s):  
Diesel Engine ◽  
Large Scale ◽  
Process Models ◽  
Development Programs ◽  
Industrial Case Study ◽  
Additional Information ◽  
Engine Design ◽  
Team Interactions ◽  
Product And Process

AbstractSuccessful realization of large-scale product development programs is challenging because of complex product and process dependencies and complicated team interactions. Proficient teamwork is underpinned by knowledge of the manner in which tasks performed by different design participants fit together to create an effective whole. Based on an extensive industrial case study with a diesel engine company, this paper first argues that the overview and experience of senior designers play an important part in supporting teamwork by coordinating activities and facilitating proactive communication across large project teams. As experts move on and novices or contractors are hired, problems are likely to occur as tacit overview knowledge is lost. If informal, overview-driven processes break down, the risk of costly oversights will increase, and greater management overhead will be required to realize successful product designs. Existing process models provide a means to express the connectivity between tasks and components thus to compensate partially for the loss of tacit overview. This paper proposes the use of design confidence, a metric that reflects the designer's belief in the maturity of a particular design parameter at a given point in the process, to address the limitations of existing models. The applicability of confidence-based design models in providing overview, as well as their shortcomings, will be demonstrated through the example of a diesel engine design process. Confidence can be used to make overview knowledge explicit and convey additional information about the design artifact, thereby informing communication and negotiation between teams.

A Measure of the Information Loss for Inspection Point Reduction

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Kristina Wärmefjord ◽  
Johan S. Carlson ◽  
Rikard Söderberg
Keyword(s):  
Cluster Analysis ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Multiple Regression ◽  
Automotive Industry ◽  
Information Loss ◽  
Small Subset ◽  
Efficiency Measure ◽  
Point Reduction ◽  
Highly Correlated

Since the vehicle program in the automotive industry gets more and more extensive, the costs related to inspection increase. Therefore, there are needs for more effective inspection preparation. In many situations, a large number of inspection points are measured, despite the fact that only a small subset of points is needed. A method, based on cluster analysis, for identifying redundant inspection points has earlier been successfully tested on industrial cases. Cluster analysis is used for grouping the variables into clusters, where the points in each cluster are highly correlated. From every cluster only one representing point is selected for inspection. In this paper the method is further developed, and multiple linear regression is used for evaluating how much of the information is lost when discarding an inspection point. The information loss can be quantified using an efficiency measure based on linear multiple regression, where the part of the variation in the discarded variables that can be explained by the remaining variables is calculated. This measure can be illustrated graphically and that helps to decide how many clusters that should be formed, i.e., how many inspection points that can be discarded.

scholarly journals An industrial case study: QbD to accelerate time-to-market of a drug product

AAPS Open ◽  
2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Madalena Testas ◽  
Tiago da Cunha Sais ◽  
Leonardo Piccoli Medinilha ◽  
Katia Nami Ito Niwa ◽  
Lucas Sponton de Carvalho ◽  
...  
Keyword(s):  
Process Development ◽  
Drug Product ◽  
Pharmaceutical Products ◽  
Product Knowledge ◽  
Industrial Case Study ◽  
Actual Application ◽  
Product And Process Knowledge ◽  
Product And Process ◽  
Regulatory Flexibility

AbstractThe use of a Quality by Design (QbD) approach in the development of pharmaceutical products is known to bring many advantages to the table, such as increased product and process knowledge, robust manufacturing processes, and regulatory flexibility regarding changes during the commercial phase. However, many companies still adhere to a more traditional pharmaceutical process development—in some cases due to the difficulty of going from a theoretical view of QbD to its actual application. This article presents a real-world case study for the development of an industrial pharmaceutical drug product (oral solid dosage form) using the QbD methodology, demonstrating the activities involved and the gains in obtaining systematic process and product knowledge.

Tolerance Simulation of Compliant Sheet Metal Assemblies Using Automatic Node-Based Contact Detection

2008 ◽  
Author(s):  
Kristina Wa¨rmefjord ◽  
Lars Lindkvist ◽  
Rikard So¨derberg
Keyword(s):  
Simulated Data ◽  
Simulation Software ◽  
Contact Detection ◽  
Contact Modeling ◽  
Industrial Case Study ◽  
Critical Dimensions ◽  
Finite Element Software ◽  
Inspection Data ◽  
Variation Simulation

Tolerance simulation is a crucial tool for predicting the outcome in critical dimensions, and is used during early phases of product development in automotive industry. In order to increase the accuracy and the agreement with reality of the predictions even further, variation simulation software offer in some cases the possibility to perform compliant analysis, i.e. the parts are not restricted to be rigid. In compliant analysis contact modeling is an important feature. In this paper a simplified method for automatic contact detection, well suited for tolerance simulations, is suggested. Traditionally, those kinds of non-rigid simulations are very time consuming, but by using this kind of simplified contact modeling in the Monte Carlo simulations, the simulation times can be kept down. The method is tested on an industrial case study. The analyses are done with and without contact modeling and those results are compared to real inspection data. The contact modeling turns out to be an important feature; the correlation between the results with contact modeling and inspection data is much stronger than the correlation for simulations without contact modeling. When using the new contact modeling algorithm the correspondence between simulated data and inspection data is very satisfying and the algorithm seems to be faster than traditional finite element software.

A Methodology for Incorporating Ergonomics into Manufacturing Systems Design

2002 ◽  
Vol 46 (13) ◽  
pp. 1022-1026
Author(s):  
Victor Paquet ◽  
Li Lin
Keyword(s):  
Design Process ◽  
Computer Simulations ◽  
Manufacturing Systems ◽  
Production Capacity ◽  
Systems Design ◽  
Labor Cost ◽  
System Throughput ◽  
Industrial Case Study ◽  
Manufacturing Systems Design

Approaches to manufacturing systems design often utilize a sequential procedure that focuses on the use of new and available technologies to improve production capacity, with the roles of employees in production processes considered much later. This study developed a methodology that integrates both manual and computer simulations to evaluate system performance and identify ergonomic problems early in the system design process. Information about operator performance and potential ergonomic risk factors is obtained through manual simulations, and estimates of operator utilization and system throughput are obtained through computer simulations. An iterative design process is used, with the results of manual and computer simulations informing each other during subsequent simulations. The results of an industrial case study in which the methods were applied to the design of a manufacturing cell demonstrate that the methodology can be used to design manufacturing systems with significant savings in labor cost and improved manufacturing system flexibility.

Integrated Product and Process Modelling

2003 ◽  
Author(s):  
Patrik Nilsson ◽  
Bjo¨rn Fagerstro¨m
Keyword(s):  
Process Modeling ◽  
Concurrent Engineering ◽  
Product Modeling ◽  
Commercial Software ◽  
Industrial Case Study ◽  
Related Information ◽  
Proposed Model ◽  
Product And Process ◽  
Important Basis

This paper presents a model for integrated product and process modeling. The aim is to investigate how product and process related information could be structured and managed in order to bridge the gap between the product and the process. Integrated product and process modeling is an important basis for concurrent engineering, as it provides a shared representation of the evolving design. First, an introduction to product modeling is discussed. Then, the proposed model, theoretically based on chromosome model, is presented. Second, process modeling is discussed, and more common tools/methods for process modeling are presented. Third, and finally, an industrial case study is presented, where the proposed model has been applied and evaluated in commercial software.

A Measure of the Information Loss for Inspection Point Reduction

2008 ◽  
Author(s):  
Kristina Wa¨rmefjord ◽  
Johan S. Carlson ◽  
Rikard So¨derberg
Keyword(s):  
Cluster Analysis ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Multiple Regression ◽  
Automotive Industry ◽  
Information Loss ◽  
Small Subset ◽  
Efficiency Measure ◽  
Point Reduction ◽  
Highly Correlated

Since the vehicle program in automotive industry gets more and more extensive, the costs related to inspection increase. Therefore, there are needs for more effective inspection preparation. In many situations, a large number of inspection points are measured, despite the fact that only a small subset of points is needed. A method, based on cluster analysis, for identifying redundant inspection points has earlier been successfully tested on industrial cases. Cluster analysis is used for grouping the variables into clusters, where the points in each cluster are highly correlated. From every cluster only one representing point is selected for inspection. In this paper the method is further developed and multiple linear regression is used for evaluating how much of the information that is lost when discarding an inspection point. The information loss can be quantified using an efficiency measure based on linear multiple regression, where the part of the variation in the discarded variables that can be explained by the remaining variables is calculated. This measure can be illustrated graphically and that helps to decide how many clusters that should be formed, i.e. how many inspection points that can be discarded.

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