The symposium concerns the topic of robust design from a practical and industry orientated perspective. During the 2 day symposium we will share our understanding of the need of industry with respect to the control of variance, reliability issues and approaches to robust design. The target audience for the symposium therefore will aim to attract equal numbers of industry and academic delegates with two separate paper submission tracks.

For more information please contact:
Chair: Thomas J. Howard
Co-chair: Tobias Eifler

Time Schedule/Event

DAY 1:

8:00

Bus departs from Conference Hotel

8:30

Coffee

8:45

Registration

9:00

Welcome introduction

Thomas J. Howard Head of Robust Design Group, DTU 

The International Symposium on Robust Design is a dedicated meeting where academics and industry delegates meet to discuss the challenges and advances in robust design and related topics.

The principle benefits of robust design are widely accepted. Robustly designed products are less sensitive to variation and are therefore easier to produce, more reliable during operation with a more consistent quality. However, there is still a large gap between robust design in theory and robust design in practice during product development. Many of the current approaches are slow and difficult to use and often are only applicable at later stages when design change is less feasible.

The symposium has greater focus on applied robust design, focusing on operationalising robust design research for use in product development. The symposium has therefore been constructed as a more hands on and dialogue based, with workshop exercises and software demonstrations as well as the usual podium and poster presentation.

ISoRD14 is hosted by the Robust Design Group at DTU Mekanik and is the official symposium of the Design Society affiliated Robust Design Special Interest Group - see http://robustdesign.org for more details. This year, ISoRD is proudly sponsored by Novo Nordisk the world's leading provider of diabetes care and champions of Robust Design, and Valcon Design, the consultancy group pioneering the Six Theta® Robust Design methodology.

9:10

Robust design, Predictable innovation

Niels Hansen, Chief Engineer, Novo Nordisk Device R&D 

Novo Nordisk is a Danish owned pharmaceutical company having more than 40.000 employees. Novo Nordisk is perhaps best known as the provider of medicines, especially insulin to diabetics but also medicines to treat growth hormone deficiency and haemophilia.

Insulin is a hormone that controls the blood sugar and it needs to be injected in the skin at least once a day, but some treatment regimens requires up to 6 injections a day. As blood sugar needs to be controlled in very narrow span (not too high to avoid serious late complications and not too low to avoid acute unconsciousness and even death.) insulin injections needs to be very precise (typically within ± 5% of 100 - 400 µL).

Novo Nordisk has for more than 25 years provided injection devices mainly insulin pens to people with diabetes for making the frequent injections precise and more convenient to perform. Using Insulin pens is today the state-of-the art treatment.

Unfortunately the number of insulin using diabetics has increased dramatically over the last decade, and keeps increasing all over the world.

The challenge for Novo Nordisk in these and the coming years is to continue to produce and supply high quality insulin pens from different production sites over the world in very high and increasing numbers (several hundred million pieces/year) to the customers.

It is important for Novo Nordisk to design devices that fulfil real customer needs. Equally important is it to make device designs robust so they can be produced in very high numbers, at a very high quality level and with a very high level of predictability both during the project phase and during the subsequent production. Novo Nordisk Device R&D started focusing on robust design in 2011 and now implements robust design principles already when drafting a device design in the very early project phases. Novo Nordisk is proud to support the ISoRD14 symposium which will help to bring state of the art knowledge on Robust Design into practice.

9:20

Denmark: Excellence in Mechanical Design

Janus Juul Rasmussen, CEO Valcon Design 

It is a great pleasure to see the creation of a symposium dedicated to the subject of Robust Design. Robust Design is an extremely important and valuable paradigm for production companies. In a globalised market, companies must compete on price, quality and being first on the market with new products. As a consequence, most companies have well-described product development and quality assurance processes to ensure that the products are developed fast have a desired quality level prior to launch.

However, many companies still struggle with their production ramp-up, i.e. going from a finished design to a full-speed production. During this phase, the companies are faced - for the first time - with the true variation of their production and assembly setup, leading to delayed product launches, high internal scrap rates, and extensive quality control procedures - all of which leads to a loss to both the company and to society.

Robust Design is an important paradigm for smoothing the way from design to production as it provides methods and processes to forecast and mitigate the consequences of variation. Unfortunately, surveys have shown that Robust Design Methods are not adopted by industry, primarily because the methods have been too complex and focused on statistics for the development engineers to use them.

I believe that ISoRD14 can help bridge this gap. With delegates from both industry and academia and combination of presentations, discussions and workshops, the framework is provided for a fruitful exchange of ideas, methods and knowledge.

9:30

Keynote 1  Robust Design Impact in Industry

Martin Ebro, DTU/Valcon Design

Product development from idea to market. Hands-on experience as a design engineer on a wide variety of products including consumer electronics, wind turbines, medical devices and automotive products.

Experienced within product development processes, methods and metrics, specifically within the field of Robust Design. Responsible for developing, implementing and teaching robust design tools and methods.

Current work involves: PhD Candidate at DTU, consultant at Valcon Design, teaching at DTU and in industry, external lecturer.

Specialties:
Robust Design
Interface Design
Tolerance Design
Kinematic Design
Product development processes
Geometrical Dimensioning and Tolerancing (GD&T / GPS)
Mechanism Design

10:00

Break

Oral Session 1 - Robustness in Design

10:30

Industry Case 1  Prediction of Glass Cartridge Robustness in Assembly line Loading

Torben Hansen, Novo Nordisk

Each year Novo Nordisk produces multimillion injection devices incorporating drug contained glass cartridges. These cartridges will inevitably be subjected to various loadings in both line feeding systems and in the device assembly rigs. It is obviously crucial to preserve the structural cartridge integrity and avoid any form of cracking and fragmentation of the glass for the full life time of the devices. The robustness is quantified by a safety factor against cracking. As shown in figure 1, it implies that both assembly line loadings and the strength of the sub-supplied cartridges are determined along the location of max stress in relation to the rotatory position of the weakest region. These figures can be used to specify the loading for the incoming inspection and prevent future device designs from overloading the cartridges. The cartridge glass is brittle with a low cracking energy and sensitive to impact loading. The glass strength is determined by microscopic manufacturing related imperfections (which have no influence on the performance and integrity of the final device) and is both loading mode and rate dependant. Thus a conventional material property such as the ultimate stress cannot be used to calculate a safety factor. Matters are further complicated by loadings being tolerance dependant and by the fact that each cartridge has a randomised position of the weakest region relative to the maximum loading. This calls for a statistical based calculation of the safety factor. Figure 2 shows an example on a safety margin without distribution overlap. In some cases a limited distribution overlap might be acceptable.

11:00

Scaling Under Dynamic Uncertainty Using Laws of Growth

Julian Lotz, TU Darmstadt

In size range development the designer has to face uncertainty that changes with the scaled parameters of the product. These parameters can be geometric properties, power, loads or cost. Uncertainty occurs in all stages of the product lifecycle. This paper addresses uncertainty that occurs during the usage of the product. Uncertainty in usage processes is often induced by wear, load (fatigue), aging or corrosion. These effects often refer to the product's size.
In size range development methodology two ways of scaling are common: dimensional analysis and the use of laws of growth. Both are able to consider uncertainty (estimated and stochastic uncertainty). For the static description of scaled product properties, literature offers adequate approaches facing this uncertainty. One of them uses scenario laws of growth (best case and worst case) to handle estimated uncertainty whereas Monte Carlo simulation to handle stochastic uncertainty.
This paper offers a procedure model of how to face dynamic estimated or dynamic stochastic uncertainty. The outputs of the static procedures described in literature (Monte Carlo and scenario laws of growth) are used as input for a second procedure considering the dynamic aspects of uncertainty. First, time dependent scenario laws of growth are developed. Time dependent Monte Carlo simulation is performed to determine the mean value of a product property during product use, not just the mean value right after production. A set of time dependent laws of growth that describe statistical parameters size range products are derived. The results of the Monte Carlo simulation are compared to the results dynamic scenario laws of growth show for estimated uncertainty. A calculation of the error made by using dynamic scenario laws of growth is performed and its assessment is discussed.

11:20

A Comparative Study on Tolerance Analysis Approaches

Benjamin Schleich, FAU

Robust product designs are characterized by their insensitivity to disturbances and noise, such as geometric part deviations, which are inevitably observed on every manufactured workpiece. These observed deviations are covered by the axioms of manufacturing imprecision and measurement uncertainty, which convey the concepts of variability and uncertainty as fundamental aspects of robust design. In order to ensure the product function though the presence of these geometric part deviations without building physical artefacts, tolerance simulations are employed in the context of computer-aided tolerancing. Motivated by the shortcomings of existing tools, the concept of Skin Model Shapes has been developed as a novel paradigm for the computer-aided tolerance analysis. This paper presents a comparative study on the standard procedure for the tolerance analysis employing proprietary CAT tools and the tolerance simulation based on Skin Model Shapes, where a focus is set on the methodology and result interpretation. For this purpose, exemplary study cases are highlighted. Based on the comparisons, recommendations for the use of CAT tools in the context of tolerance analysis and robust design are derived.

11:40

Design Guidance for Robust Design

Valter Loll, Loll Consult

The short product development cycle and the increased demand of robust, safe and reliable design has made the Test Analysis And Fix (TAAF) method obsolete. Closing the feedback loop on a design from field return (FRACAS) takes years. Closing the feedback loop from testing take months. Therefore a modern design has to build in robustness, safety and reliability during the design process. The paper describes how the Load-Strength theory and other methods can be used to develop design guidance for a robust design. The influence of safety margin and loading roughness is described together with repeated loads. Real examples of design guidance for robustness are shown.

12:00

Lunch

13:00

Robust Design Workshop: A forensic engineering case

During this workshop the delegates will be placed into teams. They will be given a product and a case file with clues to the product's failure and the major incident that incurred. Included in the case files will be engineering drawings, specifications, reliability test results, CAD drawings and various other useful bits of information. Working in your groups you will discuss and analyse the design and work out what the problems were, how to solve the problem both in terms of a quick fix and in terms of long term design improvement. Teams will be encouraged to bring their own robust design methods to the table and to discuss their applicability both now and when the design was being developed. The session will finish with a round of presentations of key findings and improvements followed by pre-prepared expert analysis of the cases and what exactly went wrong.

For workshop details see here: www.robustdesign.org/workshop/

15:00

Break

17:00

Bus departs from Conference

20:00

Conference Dinner

DAY 2:

8:00

Bus departs from Conference Hotel

8:30

Coffee

8:45

Rapid results with robust design

Torben Bygvraa Rasmussen, NNE Pharmaplan

Robust design that is insensitive to component variation is of course vital for minimizing product quality issues and ensuring low cost. However obtaining robust design requires the capability to evaluate the design robustness and eventually optimize it – and many producers find it difficult to ”get started” – especially in a way, where results can be demonstrated fast. It is our experience, that a good way to get started is to involve the right people from Marketing, R&D, production and QA/QC, and train dedicated people in the use of ”easy to access” software such as Vartran for finding optimal targets (minimizing the effect of component variation on product functionality), and excel for tolerance analysis. This allows for a fast start where the tolerance analysis may be adapted to the special needs of the producer to ensure the most reliable results.

09:00

Computer Aided Robust Design session

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CETOL 6σ tolerance analysis

CETOL 6σ tolerance analysis software provides product development teams with the insight required to confidently release designs to manufacturing. Precise calculation of surface sensitivities exposes the critical-to-quality dimensions in the assembly. Utilizing advanced mathematical solutions, this tolerance analysis solution accelerates optimization to achieve robust designs ready for manufacturing.

Fully integrated with Pro/ENGINEER® and Creo®, SolidWorks®, CATIA®

Ͱ

Sigmetrix GD&T Software

A necessary function of the design process, Geometric Dimensioning and Tolerancing (GD&T) is often perceived as a tedious, manual exercise where specifications are drawn by hand and applied to CAD drawings as a separate step.

Enter GD&T Advisor - the preferred GD&T software solution that empowers designers to communicate permissible levels of imperfection in real-world manufactured parts, all from within the CAD environment.

Ͱ

OPTIMUS® - Advanced Design Exploration

Input variability is the source of unexpected and often unintended product behavior. Even at world-class manufacturers, it may occur that a design successfully passes deterministic simulation, while some of manufactured items fail production quality control. To avoid this problem in the design stage, the robust design optimization software Optimus takes into account the variability of the design variables, and subsequently applies robustness and reliability concepts and methods to ensure a robust and reliable design.

L

JMP - Statistical Discovery from SAS

Achieving high quality and reliability requires a passion for, and dedication to, continuous learning and improvement. Systematically using data to determine more efficient and effective ways to get things done delivers better products, services and levels of organizational performance, for small or large companies alike.

JMP provides the full spectrum of capabilities to help engineers, scientists and researchers to apply statistical thinking, helping them to develop and deliver products and services that consistently meet or exceed customer expectations, reduce time to market and warranty costs, and build and protect brand image.

10:15

Break

10:30

Poster Session

Ͱ

A Robust Design Methodology Process

Ida Gremyr, Chalmers University

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Methodology to identify an ideal point of time for performing a FMEA during the product development process

Jan Würtenberger, TU Darmstadt

Ͱ

Sensitivity Analysis of Tolerances which Restrict Multiple Similar Geometry Elements

Philipp Ziegler, FAU

Ͱ

Systematic Method for Axiomatic Robustness-Testing (SMART)

Stefan Kemmler, University of Stuttgart

Categorisation RDMs

Moritz Göhler, DTU

11:30

Industry Case 2 Validation of Customer Requirements by System Simulation Taking Tolerances and System Variations into Account

Matthias Ehlert, BMW

The aim of the following contribution is to introduce an integrated process which allows the implementation of factors that have a significant impact on the limiting positions. These limiting positions and their effects on geometric deviations and displacements need to be investigated in order to ensure that functional aspects of an assembly are fulfilled for large quantities.
The presented approach involves the finding of these limiting positions using statistical methods and state-of-the-art tools as well as the simulation of the flexible and compliant components. It will be illustrated in connection with the environment of a modern vehicle entry. A simplified section of the geometry is used to explain the planned procedure. The proposed process is divided into three major steps. The first step includes the implementation of a rigid tolerance simulation, which delivers information about probability distributions in order to determine the limiting positions. Second, a finite element analysis (FEA) of the door sealing system under geometric deviations in accordance to the results of the 3DCS simulation is performed. Third, a FEA of the door and the side frame, providing corresponding deformation data, leads to the limiting positions with regard to the elastic system behavior.
Finally, this process enables the user to evaluate the system behavior of a door assembly with respect to the limiting positions in more detail.

12:00

Lunch

Oral Session 2 - Robustness in Production

13:00

Keynote 2 LEGO's production challenge: maintaining process capability and product quality while increasing production volume and bringing new products to the market.

Rikke Andersen, Six Sigma Engineer / LEGO System A/S

LEGO is one of the leading brands of the toy industry. One of core values is the play promise: a positive playing experience for every child each time it plays with LEGO.
A simple but vitally important characteristic for LEGO, is that all bricks should fit together with a consistent strength press fit. While this is challenging enough, over the years this quality characteristic, among others, have had to be maintained under ever increasing production volumes and the launch of many novel products. In the attempt to deliver the desired quantity on time, many factors can affect the risk profile in a negative way. The risk of losing the overview of implemented changes and their consequences is high, leading to new/potential problems are not detected and known problems are not solved. The presentation will cover some of the initiatives and work processes, which are used to support a positive development in the process capability and controls despite the growth, in order to deliver the right quality of the LEGO bricks.

13:30

Robust Design Principles to Evaluate Additive Manufacturing Capabilities

Iñigo Flores, Aalto University

Additive manufacturing (AM) is generating a paradigm shift by expanding the manufacturing capabilities. However, quality of AM produced parts is dependent on a number of machine, geometry and process parameters. The impact of inputs, such as the machine technology, the part orientation, the part location and the quality of the digital data, affects the AM outcomes drastically. A user of such type of equipment faces the problem of selecting optimal sets of input variables and therefore, it is necessary to support this selection process that is based typically in tacit knowledge of the machine operator or service suppliers.
The present research has proposed a framework integrating Taguchi design of experiments, multi-objective optimization and statistical process control, to optimize the manufacturing process and fulfil multiple requirements imposed to an arbitrary geometry. During the experiment, three conflicting requirements were imposed to a case geometry. Two of them, at the macro level, evaluated dimensional and geometrical tolerances. The third one, at the micro level, evaluated the surface quality of the produced parts. The outcomes of the experiment indicate that only one machine (M1, Stereolithography), was feasible to simultaneously fulfil macro and micro level requirements. However, the variability of the process was not sufficiently low, and the mean values centred to classify the process as capable according to production standards.
This study demonstrates that a combined usage of design of experiment and standardized capability analysis can be applied for selecting the most suitable machine and process parameters. The robustness analysis proposed by Taguchi methods has not been directly considered in this research due to the selected size of the orthogonal array. A supplementary study including the impact of noise factors is planned for future research.

13:50

Robust Design of active Systems - an approach to consider disturbances within the selection of sensors

Tillmann Freund, TU Darmstadt

Uncertainty occurs in every phase of the product lifecycle, while the properties of the product and thus its corresponding behavior regarding influence parameters are mostly determined during the development phase. One goal of product development is therefore the atic support of the development of robust products. To achieve this goal, uncertainty must be methodically identified, analyzed and finally controlled by purposeful operations. One way to control emerging uncertainty is the application of active systems, for example the application of a feed-forward controller within a machine to compensate for reduced stiffness compared to a regular machine. On the other side, the use of active-control-systems generally increases a system's complexity and creates additional uncertainty. In order to handle these conflicting factors a methodical approach is presented within this paper that contains apropriate models, criteria and procedures to asses the inherent uncertainty of active/adaptive systems. The information obtained can then be used to develop robust active-/adaptive-systems.
The SFB 805 process model is based on the SADT model and is used to detect uncertainty along process chains. The uncertainty is allocated to the process and the influencing parameters resources, people, information and disturbances. In addition, for the investigation of active systems, interactions between process and product must be taken into consideration. Accordingly, the process model is extended with reference to Heidemann whereas the product model is designed similar to the model of o according to Nordmann. The various model elements are designed as a modular kit and can be combined to consider particular product structures.
In order to evaluate the model a multi purpose machine and a free bending process supported by an adaptive feed-forward controller is being modeled. Hence, the sensor/controller-behavior considering the influence of disturbances is examined by using the list of normalised disturbances. The control of the occurring uncertainty finally takes place using a design catalogue for sensors enhanced about aspects of uncertainty, to support the designer at their selection.

14:10

Robust Design Process for the Dimensional and Geometrical Features on Cold Formed Components

Julian D. Booker, Bristol

Plain spherical bearings are precision assemblies with a low frictional moment finding wide application in industry where they operate in harsh environments. They are manufactured using a cold forming process known as 'nosing'. An experiential approach is currently used by a manufacturer to develop new bearing products and determine associated process settings for the nosing process. Typically, inefficiencies can be observed for the bearing assembly post-nosing where any one of nine different failure modes may occur leading to rework or scrap costs due to a number of component and process inconsistencies. The initial focus is the outer bearing shell component and the geometrical relationships of the end chamfer features. Process capability measures are developed for a bearing model, with parts individually tracked through the nosing process to examine the influence out-of- tolerance variation on process integrity, measured forming loads and frictional moment. A validated Finite Element (FE) model is used to predict the complex elastic-plastic material behaviour at high strain-rates in the nosing process to support the simulation of in-process failure modes. These models take into account the geometrical and dimensional variations of the chamfers, material property variation and coefficient of friction. Predictions are made for feature process capabilities which produce lower failure rates in production. The robust design process outlined concludes with improved component and process design, and to aid the development of future bearing products using nosing.

14:30

Closing Session

15:00

Farewell drinks reception

16:00

Bus departs from Conference

20:00

Food & Drinks at Christiania

Chair: Thomas J. Howard

Associate Professor

DTU MECHANICAL ENGINEERING
Department of Mechanical Engineering

Ph. +45 45 25 47 41
thow@mek.dtu.dk

Co. Chair: Tobias Eifler

Postdoc

DTU MECHANICAL ENGINEERING
Department of Mechanical Engineering

tobeif@mek.dtu.dk

Martin Ebro

Reliability Specialist
Valcon A/S & Novo Nordisk

DTU MECHANICAL ENGINEERING
Department of Mechanical Engineering

maec@mek.dtu.dk

Simon Moritz Göhler

PhD Student

DTU MECHANICAL ENGINEERING
Department of Mechanical Engineering

simogo@mek.dtu.dk

Søren Nygaard Pedersen

PhD Student

DTU MECHANICAL ENGINEERING
Department of Mechanical Engineering

snyped@mek.dtu.dk

Aryan Christiansen

Research Assistant

DTU MECHANICAL ENGINEERING
Department of Mechanical Engineering

s112979@student.dtu.dk

Andreas Rafn

Research Assistant

DTU MECHANICAL ENGINEERING
Department of Mechanical Engineering

s110561@student.dtu.dk