Professor Cris Arnold

Professor, General Engineering

+44 (0) 1792 295749

j.c.arnold@swansea.ac.uk

Academic Office - A_214
Second Floor
Engineering Central
Bay Campus

Available For Postgraduate Supervision

Research Links

https://orcid.org/0000-0002-8937-1355

About

Cris Arnold is Deputy Head of College and Director of Learning and Teaching for the Department of Engineering, with oversight of all of the undergraduate and taught masters programmes within Engineering. In addition to this role, he is actively engaged with teaching at all levels, especially in the areas of polymer and composite materials, but also extending to structural analysis and environmental issues.

He has a long experience of working collaboratively with industry, on joint research projects, technology transfer and industry-embedded education. This includes supervision of over 40 doctorate and masters students and almost 100 publications with an H index of 17. He leads the Degree Apprenticeship schemes in Engineering, delivered in partnership between Swansea University and Coleg Cambria.

Areas Of Expertise

Mechanical performance and characterisation of polymer and composite materials
Long-term durability, including degradation and weathering mechanisms
Environmental impact assessment and recycling of materials

Career Highlights

Teaching Interests

Materials Engineering, especially polymers and composites
Structural analysis and mechanical performance of materials
Environmental impact assessment and life cycle analysis
Engineering Education, especially the collaborative provision with industrial partners

Research

Publications

Research Highlights

Al-Salem, S., Behbehani, M., Al-Hazza’a, A., Arnold, J., Alston, S., Al-Rowaih, A., Asiri, F., Al-Rowaih, S., Karam, H., Arnold, C., & Alston, S. (2019). Study of the degradation profile for virgin linear low-density polyethylene (LLDPE) and polyolefin (PO) plastic waste blends. Journal of Material Cycles and Waste Management
https://doi.org/10.1007/s10163-019-00868-8, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa50451
Arnold, J. & Arnold, C. (2007). Environmental Effects on Crack Growth in Composites. Comprehensive Structural Integrity-470).
https://doi.org/10.1016/B978-008043749-1/00318-8, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19162
Korkees, F., Arnold, C., & Alston, S. (2018). Water absorption and low-energy impact and their role in the failure of ±45° carbon fibre composites. Polymer Composites, 39(8), 2771-2782.
https://doi.org/10.1002/pc.24269, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa31405
http://dx.doi.org/10.1002/pc.24269
Huszar, M., Belblidia, F., Arnold, J., Bould, D., Sienz, H., & Arnold, C. (2014). An exploration of core misalignment, shifting and deflection phenomena through thickness measurements on thin-walled injection moulded bins. In Sustainable Design and Manufacturing (SDM) Conference, Cardiff 28-30 April, 2014.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19161
Alexander, R., Arnold, J., Alston, S., Searle, J., & Arnold, C. (2014). Thermal Analysis as a Tool for Assessing the Degradation of PVC-coated Constructional Steel.. In International Conference & Exhibition on Advanced & Nano Materials. Calgary, Canada.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19160
Mehmood, S., Sienz, H., Lavery, N., Alston, S., Arnold, J., & Arnold, C. (2014). Studying Microstructure and Crystallinity of Polypropylene in an Injection Moulded Medical Bin Lid.. In In Kess International Sustainable Design and Manufacturing. Cardiff, Wales.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19159
Arnold, J., Alston, S., Korkees, F., & Arnold, C. (2012). The Long-Term Water Absorption and Desorption Behaviour of Carbon-fibre / Epoxy Composites. In Proceedings of the 15th European Conference on Composite Materials,ESCM.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19158
Arnold, J., Alston, S., Korkees, F., & Arnold, C. (2012). Finite element modelling of moisture uptake in carbon fibre / epoxy composites: a multi-scale approach. In Proceedings of the 15th European Conference on Composite Materials,ESCM.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19157
Arnold, J., Twist, B., Jones, R., Khan, N., & Arnold, C. (2012). Bonded Repair of CFRP Primary Structure: testing and analysis of bonded scarf joints. In Proceedings of the 15th European Conference on Composite MaterialsESCM.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19156
Arnold, J. & Arnold, C. (2003). Environmental Effects on Crack Growth in Polymers. Comprehensive Structural Integrity-319).
https://doi.org/10.1016/B0-08-043749-4/06123-1, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19147
Arnold, J., Venditti, N., & Arnold, C. (2001). The Effects of Environment on the Creep Properties of a PEMA based Bone Cement. , 707-717.
https://doi.org/10.1023/A:1011272626846, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa2031
Brennan, L., Isaac, D., Arnold, J., & Arnold, C. (2002). Recycling of Acrylonitrile-Butadiene-Styrene and High Impact Polystrene from Waste Computer Equipment. , 572-578.
https://doi.org/10.1002/app.10833, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa2032
Arnold, J., O'Brien, F., Moody, M., & Arnold, C. (2006). All Polymer Composites from Recycled Woven Polypropylene Fabrics and Polyethylene Film. , 1523-1529.
https://doi.org/10.1002/pen.20614, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa2033
Arnold, J., Arnold, C., & Griffiths, I. (2011). The dynamic behavior of squash balls. American Journal of Physics
https://doi.org/10.1119/1.3531971, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5443
Arnold, J. & Arnold, C. (2009). Influence of production parameters on surface energy of tinplate. Ironmaking & Steelmaking
https://doi.org/10.1179/174328109X422557, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5444

All Research

Journal Articles

Alston, S., Arnold, C., Swan, M., & Stone, C. (2021). A source‐sink model for water diffusion in an activated carbon fiber/phenolic composite. Polymer Composites, 42(7), 3550-3561.
https://doi.org/10.1002/pc.26078, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa56994
http://dx.doi.org/10.1002/pc.26078
Alston, S., Arnold, C., Swan, M., & Stone, C. (2021). The Use of Single-Sided NMR to Study Moisture Behaviour in an Activated Carbon Fibre/Phenolic Composite. Applied Magnetic Resonance, 52(2), 99-115.
https://doi.org/10.1007/s00723-020-01273-3, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa55332
Al-Salem, S., Behbehani, M., Al-Hazza’a, A., Arnold, J., Alston, S., Al-Rowaih, A., Asiri, F., Al-Rowaih, S., Karam, H., Arnold, C., & Alston, S. (2019). Study of the degradation profile for virgin linear low-density polyethylene (LLDPE) and polyolefin (PO) plastic waste blends. Journal of Material Cycles and Waste Management
https://doi.org/10.1007/s10163-019-00868-8, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa50451
Korkees, F., Alston, S., & Arnold, C. (2018). Directional diffusion of moisture into unidirectional carbon fiber/epoxy Composites: Experiments and modeling. Polymer Composites, 39(S4), E2305-E2315.
https://doi.org/10.1002/pc.24626, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa36153
Korkees, F., Arnold, C., & Alston, S. (2018). Water absorption and low-energy impact and their role in the failure of ±45° carbon fibre composites. Polymer Composites, 39(8), 2771-2782.
https://doi.org/10.1002/pc.24269, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa31405
http://dx.doi.org/10.1002/pc.24269
Murmu, T., Sienz, J., Adhikari, S., Arnold, C., Arnold, C., Sienz, J., & Adhikari, S. (2013). Nonlocal buckling of double-nanoplate-systems under biaxial compression. Composites Part B: Engineering, 44(1), 84-94.
https://doi.org/10.1016/j.compositesb.2012.07.053, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa12500
James, S., Robinson, A., Arnold, J., Worsley, D., Arnold, C., & Worsley, D. (2013). The effects of humidity on photodegradation of poly(vinyl chloride) and polyethylene as measured by the CO2 evolution rate. Polymer Degradation and Stability, 98(2)-513.
https://doi.org/10.1016/j.polymdegradstab.2012.12.007, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa15702
Arnold, J., Alston, S., Korkees, F., Arnold, C., Alston, S., & Korkees, F. (2013). An assessment of methods to determine the directional moisture diffusion coefficients of composite materials. Composites Part A: Applied Science and Manufacturing, 55, 120-128.
https://doi.org/10.1016/j.compositesa.2013.08.012, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa18950
Arnold, J., Alston, S., Arnold, C., & Alston, S. (2012). Life cycle assessment of the production and use of polypropylene tree shelters. Journal of Environmental Management, 94(1), 1-12.
https://doi.org/10.1016/j.jenvman.2011.09.005, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa12497
Chandra, Y., Chowdhury, R., Scarpa, F., Adhikari, S., Sienz, J., Arnold, C., Murmu, T., Bould, D., Arnold, C., Sienz, J., & Adhikari, S. (2012). Vibration frequency of graphene based composites: A multiscale approach. Materials Science and Engineering: B, 177(3), 303-310.
https://doi.org/10.1016/j.mseb.2011.12.024, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa12499
Arnold, J., Arnold, C., & Griffiths, I. (2011). The dynamic behavior of squash balls. American Journal of Physics
https://doi.org/10.1119/1.3531971, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5443
Arnold, J., Arnold, C., & Alston, S. (2011). Environmental Impact of Pyrolysis of Mixed WEEE Plastics Part 1: Experimental Pyrolysis Data. Environmental Science & Technology, 45(21)
https://doi.org/10.1021/es201664h, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa12495
Alston, S., Arnold, J., & Arnold, C. (2011). Environmental Impact of Pyrolysis of Mixed WEEE Plastics Part 2: Life Cycle Assessment. Environmental Science & Technology, 45(21), 9386-9392.
https://doi.org/10.1021/es2016654, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa12496
Murmu, T., Sienz, J., Adhikari, S., Arnold, C., Arnold, C., Sienz, J., & Adhikari, S. (2011). Nonlocal buckling behavior of bonded double-nanoplate-systems. Journal of Applied Physics, 110(8), 084316
https://doi.org/10.1063/1.3644908, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa12498
Arnold, J. & Arnold, C. (2010). A free-volume hole-filling model for the solubility of liquid molecules in glassy polymers 1: Model derivation. European Polymer Journal, 46(5), 1131-1140.
https://doi.org/10.1016/j.eurpolymj.2010.01.016, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5445
Arnold, J. & Arnold, C. (2010). A free-volume hole-filling model for the solubility of liquid molecules in glassy polymers 2: Experimental validation. European Polymer Journal
https://doi.org/10.1016/j.eurpolymj.2010.01.017, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5446
Arnold, J., Arnold, C., Alston, S., Watson, T., & Carnie, M. (2010). The use of FTIR mapping to assess phase distribution in mixed and recycled WEEE plastics. Polymer Testing
https://doi.org/10.1016/j.polymertesting.2010.02.006, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5448
Arnold, J. & Arnold, C. (2009). Influence of production parameters on surface energy of tinplate. Ironmaking & Steelmaking
https://doi.org/10.1179/174328109X422557, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5444
Arnold, J., Alston, S., Holder, A., Arnold, C., & Alston, S. (2009). Void formation due to gas evolution during the recycling of Acrylonitrile–Butadiene–Styrene copolymer (ABS) from waste electrical and electronic equipment (WEEE). Polymer Degradation and Stability, 94(4), 693-700.
https://doi.org/10.1016/j.polymdegradstab.2008.12.019, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa5447
Arnold, J., O'Brien, F., Moody, M., & Arnold, C. (2006). All Polymer Composites from Recycled Woven Polypropylene Fabrics and Polyethylene Film. , 1523-1529.
https://doi.org/10.1002/pen.20614, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa2033
Brennan, L., Isaac, D., Arnold, J., & Arnold, C. (2002). Recycling of Acrylonitrile-Butadiene-Styrene and High Impact Polystrene from Waste Computer Equipment. , 572-578.
https://doi.org/10.1002/app.10833, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa2032
Arnold, J., Venditti, N., & Arnold, C. (2001). The Effects of Environment on the Creep Properties of a PEMA based Bone Cement. , 707-717.
https://doi.org/10.1023/A:1011272626846, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa2031

Book Chapters

Arnold, J. & Arnold, C. (2007). Environmental Effects on Crack Growth in Composites. Comprehensive Structural Integrity-470).
https://doi.org/10.1016/B978-008043749-1/00318-8, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19162
Arnold, J. & Arnold, C. (2003). Environmental Effects on Crack Growth in Polymers. Comprehensive Structural Integrity-319).
https://doi.org/10.1016/B0-08-043749-4/06123-1, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19147

Conference Contributions

Holland, P., Davies, P., Arnold, C., Leon, J., Hilaireau, N., Alves, M., Ennser, K., Cahill, S., & Hainke, M. (2019). ACTIVE CLASSROOMS ENABLING REGIONAL, NATIONAL AND GLOBAL COLLABORATION. In ICERI2019 Proceedings (pp. 7691-7699). IATED.
https://doi.org/10.21125/iceri.2019.1828, SU Repository: https://cronfa.swan.ac.uk/Record/cronfa52813
Huszar, M., Belblidia, F., Arnold, J., Bould, D., Sienz, H., & Arnold, C. (2014). An exploration of core misalignment, shifting and deflection phenomena through thickness measurements on thin-walled injection moulded bins. In Sustainable Design and Manufacturing (SDM) Conference, Cardiff 28-30 April, 2014.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19161
Alexander, R., Arnold, J., Alston, S., Searle, J., & Arnold, C. (2014). Thermal Analysis as a Tool for Assessing the Degradation of PVC-coated Constructional Steel.. In International Conference & Exhibition on Advanced & Nano Materials. Calgary, Canada.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19160
Mehmood, S., Sienz, H., Lavery, N., Alston, S., Arnold, J., & Arnold, C. (2014). Studying Microstructure and Crystallinity of Polypropylene in an Injection Moulded Medical Bin Lid.. In In Kess International Sustainable Design and Manufacturing. Cardiff, Wales.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19159
Arnold, J., Alston, S., Korkees, F., & Arnold, C. (2012). The Long-Term Water Absorption and Desorption Behaviour of Carbon-fibre / Epoxy Composites. In Proceedings of the 15th European Conference on Composite Materials,ESCM.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19158
Arnold, J., Alston, S., Korkees, F., & Arnold, C. (2012). Finite element modelling of moisture uptake in carbon fibre / epoxy composites: a multi-scale approach. In Proceedings of the 15th European Conference on Composite Materials,ESCM.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19157
Arnold, J., Twist, B., Jones, R., Khan, N., & Arnold, C. (2012). Bonded Repair of CFRP Primary Structure: testing and analysis of bonded scarf joints. In Proceedings of the 15th European Conference on Composite MaterialsESCM.
SU Repository: https://cronfa.swan.ac.uk/Record/cronfa19156

Supervision

The failure mechanisms of organic coatings on zinc aluminium magnesium substrates under exposure to natural conditions and accelerated corrosion environments (current)

EngD

Other supervisor: Prof David Penney

Other supervisor: Prof Geraint Williams
Optimising Mobility Behaviour Of Polymer Coated Packaging Steel, Protact (awarded 2022)

EngD

Other supervisor: Dr David Warren
Characterisation of Bio-Based Polymers for Use in the Packaging Industry (awarded 2023)

MSc

Other supervisor: Dr Feras Korkees
Development of Graphene Reinforced Silica Aerogel Nanocomposites (awarded 2023)

MSc

Other supervisor: Dr Feras Korkees

Taught Modules

EG-093 Fundamentals of Engineering Science 2

This course provides an introduction to the physical sciences (including the fundamentals of elementary fluid mechanics and electricity and magnetism) and their application in engineering. A practical component will be used to complement taught theory.
EG-110 Engineering Skills & Applications

Competence in engineering drawing using an industry standard CAD system and essential laboratory skills for Mechanical Engineers.
EG-133 Engineering for People Hackathon

Engineering is more than understanding technical design, it is often the social, environmental and economic context underpinning engineering solutions that determine success or failure, This has never been more relevant since the world is currently planning a radical transition to a low carbon economy while facing increased risks due to climate crisis which will bring with it unprecedented change to the world. Engineers will be at the forefront of this, and need to be equipped to tackle open-ended, unstructured and complex problems in collaboration with others. The module will allow students to explore these issues within their chosen discipline with the following structure: Each week there will be a 1-hour lecture, introducing engineering thinking and contemporary issues in global engineering design. Most activity will then take place in group-work sessions (3 hours per week), where groups of around 6 students will work in a facilitated way towards a Engineering design solution. Students will be presented with a range of Global Challenges (e.g. access to water/ off-grid energy), and over the course of the term will work to research, design and critique possible engineering solutions. The groups with the best performance in this module may have opportunities to represent Swansea University in the national Engineers without Borders UK competition.
EG-163 Design and Laboratory Classes 1

Competence in engineering drawing using an industry standard CAD system and essential laboratory skills
EG-294 Airframe Structures

This module covers the fundamentals of linear elasticity and the stress analysis of the thin-walled structural components which are commonly employed in the design of modern wings and fuselages. In particular, the bending, shearing and twisting of thin-walled beams with open, closed or multi-cell cross-sections is studied in detail. The stiffening effect of stringers is investigated and end constraints are discussed. Numerous examples demonstrate the application of the theory. The module teaches the analytical skills, but also develops the students' feeling for thin-walled structures.
EG-3080 Engineering Management (Aero, EEE, Mech)

The goal of this course is to provide the skills for professional engineers to meet the challenges of their future careers, whether they be in academia, industry, or as an entrepreneur. Irrespective of future careers engineers will be involved in projects, management and business organisations and an awareness of these issues is important for all team members. It should be recognized that the topics included in the course are not limited to scientists and engineers, they are useful for people in any careers. This course is not aimed at making you a certified project manager, but to provide the skills that will allow you to be a more effective project team member and also when you start to take on the role of project manager. With respect to business management aspects, the course will cover the basic concept of entrepreneurship before breaking down the essential elements of a business plan. The course will give the more entrepreneurial students guidance about how to go about commercialising their ideas and the less entrepreneurial students an understanding of what makes some of their colleagues tick. The learn by example approach adopted for this module guides the student through the complexities of financial and human resource management and encourages students to develop their own business plans. Students will also be introduced to the subject area of ethics, liability and responsibilities within business. This module will also provide support on careers services with students creating CVs and Linked-In accounts.
EG-M106 Polymer Processing

The module will provide a deeper understanding of the technology of plastics processing. The material covered will cross cut the engineering disciplines of advanced manufacturing technology and polymer science to broaden the technical and industrial context of polymer processing. Within the content of the module simulation software will be applied to industrial case study examples for critical evaluation. In addition, the application of polymer replication technologies within the emerging field of micro manufacturing will be presented, focusing on the advantage and limitations of size effect and length scale integration. The module will include practical demonstration laboratories and also include industrial visits.
EG-M190 Social, environmental and economic context of research

There is an increasing need for engineers to work towards complex, so called 'wicked problems', for example the secure supply of energy. This necessitates a holistic approach and involves making decisions based on a range of different factors, and consideration for economic, ethical, social, political and environmental, as well as technical limitations. Obtaining and making sense of such information involves types of knowledge and the use of tools and techniques that have not always been traditionally used within engineering disciplines. For example, ethical issues concerning negative impacts on environment or society may raise questions of value, duty or morality and requires the application of moral reasoning rather than scientific reasoning. During this module we will make use of a variety of engineering case studies which exemplify the need to consider non-technical aspects of engineering projects. We will use qualitative research approaches and ethical frameworks to help in our engineering decision making. We will also consider the role of the engineer in policy making.
EG-P11 Life Cycle Analysis and Circular Economy

This module presents the principles of life cycle analysis and Circular Economy. It covers the assessment of resource conservation by optimal use of resources, including consideration of primary extraction processes, design/manufacturing/fabrication, improving product life and end of life usage.
EGA229 Experimental Studies - Aerospace

The course introduces the students to experimental studies in a wide range of subjects relevant to Aerospace Engineering. Each experiment is self contained and the student will present the findings in written form through a lab report (or combination of lab reports and class tests) which will have a set of experiment specific questions to answer. This written reports and class tests also forms the basis for the assessment. All students work in groups and carry out five in-situ experiments and one external experiment, however the assignments are all individually submitted. The students keep a log-book of the experimental observations and results, which is used for reference for the technical report from each experiment written-up within the fortnight after the experiment.
EGH309 Advanced Materials

This module will cover the detailed mechanical behaviour of both metallic alloys and fibre composites. It will start with a recap of tensile failure mechanisms, but extend to compression and shear failures. Fracture mechanics will then be introduced as applied to metallic materials and be extended to damage accumulation methods for composite materials. Creep, fatigue and impact will be covered as will the effects of elevated temperature and external environmental conditions.
EGH314 Design for Reliability

This course is designed to equip participants with the quality and reliability engineering concepts and skills that will be needed by technically trained engineers within industrial companies to establish highly reliable and cost effective systems. The course will give introduction to the system engineering aspects of monitoring, control, reliability, survivability, integrity and maintenance. Areas of interest to be studied will encompass an engineering application from mechanical, marine and aerospace. The principles of 'Design for Reliability' will be highlighted and demonstrated with relevant examples.

Professor Cris Arnold

Telephone number

Email address

Research Links

About

Areas Of Expertise

Career Highlights

Publications

Research Highlights

All Research

Journal Articles

Book Chapters

Conference Contributions

Supervision

The failure mechanisms of organic coatings on zinc aluminium magnesium substrates under exposure to natural conditions and accelerated corrosion environments (current)

Optimising Mobility Behaviour Of Polymer Coated Packaging Steel, Protact (awarded 2022)

Characterisation of Bio-Based Polymers for Use in the Packaging Industry (awarded 2023)

Development of Graphene Reinforced Silica Aerogel Nanocomposites (awarded 2023)

Taught Modules

EG-093 Fundamentals of Engineering Science 2

EG-110 Engineering Skills & Applications

EG-133 Engineering for People Hackathon

EG-163 Design and Laboratory Classes 1

EG-294 Airframe Structures

EG-3080 Engineering Management (Aero, EEE, Mech)

EG-M106 Polymer Processing

EG-M190 Social, environmental and economic context of research

EG-P11 Life Cycle Analysis and Circular Economy

EGA229 Experimental Studies - Aerospace

EGH309 Advanced Materials

EGH314 Design for Reliability