MANUFACTURABILITY ASSESSMENT

Using Design for Manufacture Knowledge to Develop Software for a Manufacturability Analysis

Tool

Principal Researcher: Kerrie Noble Kerrie.noble.2013@uni.strath.ac.uk

4th Year (MEng) Undergraduate Product Design Engineering Student

Supervisor: Professor Xiu T Yan x.yan@strath.ac.uk

Professor of Mechatronic Systems Technology Director of Space Mechatronic Systems Technology Laboratory (SMeSTech)

Bibliography Anderson, D.M., (2010), Design for Manufacturability and Concurrent Engineering, New York, NY:

Springer Publishing

Anderson, D. M., (2013), ‘Half Cost Products’, available at http://www.halfcostproducts.com/,

accessed 05 August 2013

Benhabib, B., (2003), Manufacturing: Design, Production, Automation, and Integration, New York, NY:

Marcel Dekker Inc.

The Boeing Company, (2008), ‘High Speed Machining of Aluminium’, available at https://www.mfg-

labs.com/filedownload/Papers_Presentations/High_Speed_Aluminum_Machining_Presentation.pdf,

accessed 05 August 2013

Boothroyd, G., (2005) Assembly Automation and Product Design, Second Edition, London: Taylor and

Francis Group

Boothroyd, G., P. Dewhurst, (2012) ‘Design for Manufacture and Assembly (DFMA®) Product Costing

and Simplification’, available at http://www.dfma.com/software/index.html, accessed 05 August

2013

Bralla, J.G., (1999), Design for Manufacturability Handbook, 2 vols, Boston, Massachusetts: The

McGraw Hill Companies Inc.

Bramble, K. L., (2011), Engineering Design for Manufacturability, 5 vols, Monroe, Georgia: Engineer’s

Edge LLC.

The Centre for Automation and Intelligent Systems Research, Case Western Reserve University, (date

unknown), ‘Design for Manufacture and Assembly’, available at

http://dora.eeap.cwru.edu/gcc/dissertation/chap_4.pdf, accessed 05 August 2013

Crow, K., (1998), ‘Design for Manufacturability/Assembly Guidelines’, available at http://www.npd-

solutions.com/dfmguidelines.html, accessed 05 August 2013

Custompart.net, (2013), ‘Milling’, available at http://www.custompartnet.com/wu/milling, accessed

05 August 2013, Olney, MD

EFunda, (2013), ‘Design of Parts for Milling’, available at

http://www.efunda.com/processes/machining/mill_design.cfm, accessed 05 August 2013, Sunnyvale,

CA

First Cut, (2013), ‘CNC Machining Guidelines’, available at

http://www.firstcut.eu/gb/DesignGuidelines.aspx?awk=true, accessed 05 August 2013, Telford,

Shropshire

First Cut, (2013), ‘Threaded Holes Maximum Reach’, available at

http://www.firstcut.eu/gb/ThreadedHoles-Reach.aspx?awk=true, accessed 05 August 2013, Telford,

Shropshire

Geometric Ltd., (2013), ‘Design Guidelines for Machining’, available at

http://dfmpro.geometricglobal.com/processes/dfmpro-for-machining/, accessed 05 August 2013,

Mumbai, India

Giachetti, R. E., (1997) ‘A Decision Support System for Material and Manufacturing Process Selection’,

Journal of Intelligent Manufacturing, 9, 265 – 276

Hamidi, M., K. Farahmand, (2008), ‘Developing a Design for Manufacturing Handbook’, Paper 220, IT

302

Kazmar, D., (2011), Applied Plastics Engineering Handbook, Lowell, MA: Elsevier Inc.

Kennametal, (2013), ‘Technical Tips’, available at

http://www.kennametal.com/kennametal/en/resources/technical-tips.html, accessed 05 August

2013, Fort Mill, SC

Pro CNC Inc., (Unknown date), ‘Design Guide’, available at

http://procnc.com/images/content/Design_Guide_Rev_C.pdf, accessed 05 August 2013, Bellingham,

WA

Quick Cut CNC, (2013), ‘Design Guidelines: Things to Keep in Mind’, available at

https://quickcutcnc.com/Resources/DesignGuidelines.aspx, accessed 05 August 2013, Atlanta,

Georgia

Swaminathan, S., (Unknown Year), ‘Basic Machining Tips’, available at

https://sharepoint.ecn.purdue.edu/epics/teams/Public%20Documents/Machining%20Tips%20and%

20Steps.pdf, accessed 05 August 2013, Purdue University

Watts, S., (2005), ‘Design for Manufacture and Assembly (DFMA)’, available at

http://www.dtic.mil/ndia/2005garm/thursday/watts.pdf, accessed 05 August 2013

Weatherford, (2006), ‘Guidelines for Effective Milling’, available at

http://www.weatherford.com/weatherford/groups/web/documents/weatherfordcorp/wft040609.p

df, accessed 05 August 2013

Youseffi, K., (unkown year), ‘Design for Manufacturing and Assembly II:Design Guidelines’, Product

Design and Manufacturing Mini-curriculum, San José State University

Table of Figures Fig.2.1 A pie chart showing the associated costs of different phases within the product development process. ................................................................................................................................................... 8 Fig.3. 1 A diagram showing the process for interpreting each design guideline in order to gather information suitable for programming. ................................................................................................ 10 Fig.5. 1 A diagram showing the further definition of each design guideline to help produce mapping tables to help the programming process. ............................................................................................. 12 Fig.5.1. 1 An image illustrating the software user interface showing the 3D component which will be used for testing. .................................................................................................................................... 13

Table of Contents Abstract ................................................................................................................................................... 6

1. Introduction .................................................................................................................................... 7

2. Project Background ......................................................................................................................... 7

2.1 Project Benefits ............................................................................................................................. 8

2.2 Business Value............................................................................................................................... 8

2.3 Project Aims and Objectives ......................................................................................................... 9

3. Methodology ................................................................................................................................... 9

4. Preliminary Outcomes .................................................................................................................. 10

5. Discussion...................................................................................................................................... 11

5.1 Future Developments ................................................................................................................. 12

6. Conclusion ..................................................................................................................................... 13

6.1 Project Reflection ........................................................................................................................ 14

References ............................................................................................................................................ 15

Abstract This project was completed in order to develop a new software analysis tool in order to analyse and

optimise 3D components automatically in a hope this would reduce total cost of product development

and allow components to be produced with a shorter lead time. The project specifically focused on

Design for Manufacture guidelines related to the milling process and compiled these to produce a

database of detailed design guidelines. Each design guideline was the interpreted in terms of

conditions, values, limitations and relationships so this information could be used to produce an

intelligent, reason-based programme. The programme enables a 3D component to be imported,

analysed and changed in a simple, quick environment before cost is incurred in changing the

component design during the manufacturing phase. This tool therefore promotes concurrent

engineering. The developed software will now be tested, debugged and further developed to include

design guidelines for other manufacturing processes and tested to ensure ease of use for the operator

in terms of the user interface.

1. Introduction This project aims to develop a fundamental piece of software based on the design for manufacture

guidelines and principals which can help to reduce time in the development and manufacturing phase

involved in product development. It is hoped that a comprehensive software-based package will be

produced as a result of the outcome of this research, enabling the user to import a 3D model of a

component into a compatible package and undertake an analysis of the component, with a specific

focus on component features in relation to their suitability of use within the context of the

manufacturing process.

2. Project Background Cost reduction within the manufacturing process is seen as a vital development in the efficiency of

any modern company due to the stark economic climate in which global companies are now placed.

Losing money in a global competitive market presents the need to increase profits or cut expenses in

order to succeed.[1] Many companies are being pressurized to manufacture their products with lower

carbon footprint, better design and lower costs. It is therefore essential that a design solution is fully

evaluated from both functional and manufacturing points of view. One approach to this is to develop

a software tool to undertake the manufacturability analysis of a component automatically.

Engineering is often seen as a key activity within the manufacturing process as 70% of the cost of a

product has already been fixed at the end of the engineering phase of this process. This therefore

means that the function and the design of the product has major influences on the manufacturing

process to be selected. From this it is clear to see the close links and cooperation required between

both engineering and manufacturing phases.[3] This project aims to develop a fundamental piece of

software based on the design for manufacture guidelines and principals which can help to reduce time

in the development and manufacturing phase involved in product development, with the aim of

reducing cost within the design engineering phase where critical decisions affecting the final cost of

the product are reached.[2]

2.1 Project Benefits There are many benefits in pursuing this project, including both business value and an educational

value. The main benefits from the development of such a piece of software are outlined in more detail

below;

2.2 Business Value The business value of this project is in the potential monetary and time savings which may be

produced during the use of the developed software, this is main objective and deliverable of the

project and provides the basis for this investigation. It is hoped this time and monetary saving will be

achieved through development of software to help analyse component features and assess their

feasibility and cost effectiveness in terms of manufacturing. Reducing the time taken to develop

detailed components with correct feature characteristics will ensure efficiency for the manufacturing

process and help encourage cooperation and the adaptation of concurrent engineering across the

product development process.

Compiling a comprehensive list of design for manufacture guidelines with specific constraints and

values will be highly beneficial as most design guidelines available can be quite vague. This is especially

useful for students who are being introduced to this topic for the first time, or students in their final

year who are trying to produce a very detailed product design. This will hopefully reduce their

Fig.2.1 A pie chart showing the associated costs of different phases within the product development process.

development time and help teach them the principals of good design while also taking manufacturing

requirements into consideration alongside the design requirement, resulting in better teaching of

design principals.

2.3 Project Aims and Objectives With increasing competition from competitors and more awareness and adoption of sustainable

manufacturing, many companies are pressurized to manufacture their products with lower carbon

footprint, better design and lower costs. It is therefore essential that a design solution is fully

evaluated from both functional and manufacturing points of view to ensure the products are

manufacturable with a minimum cost and easiness. One approach to this is to develop a software tool

to undertake this manufacturability analysis of a component automatically. The main aim of the

research was to help to develop an intelligent, rule based reasoning module and test it for a prototype

software system for design feature manufacturability analysis that is being developed as part of an

ongoing international collaborative research project.

Some of the key objectives included;

• Reviewing the 4 categories of knowledge required for intelligent reasoning and

identification of potential manufacturing problems by studying the knowledge captured

by other researchers of the group

• Feasibility study of standardizing the rule elicitation and presentation for automatic rule

processing and importing into the knowledgebase;

• Testing a prototyped dynamic linking library (DLL) system of the above functionality

developed by researchers using MS visual C++ version 2008;

• Test running and debugging any problems of the DLL;

• Write a report to summarize the above work.

The above deliverables required the development of modules and testing of a pre-existing program

developed by some earlier work by the department. The project also involved implementing

geometric reasoning techniques for intelligent manufacturing, problem identification and display.

3. Methodology Outlined below is the main structure which was followed for the completion of the project;

- A review of the design for manufacture guidelines, with initial focus given to the

milling process.

- Identification of conditions, significant values and constraints of features highlighted

within the design for manufacture guidelines which have been listed.

- An analysis of the identified conditions and values which are required and appropriate

research to highlight the required values for use in defining the desired component

features.

- Summary of all collected information gathered into a spread sheet. Software

programming using the information gathered with all appropriate conditions, values

and constraints.

- Testing and analysis of developed software to ensure correct response and use within

the desired setting.

In order to prepare each Design for Manufacture Guideline for programming it was necessary to

translate the statement into a series of conditions, values, manufacturing domains and limitations.

The process followed for interpreting each Design for Manufacture Guideline is shown in the diagram

below. This approach enabled the software analysis tool to be based on mathematical reasoning and

the use of equations rather than values to give the programme more flexibility to cope with complex

designs.

4. Preliminary Outcomes Listed below are some of the main outcomes from the initial research conducted into Design for

Manufacture Guidelines for the milling process;

- 56 Design for Manufacture Guidelines for the Milling process

Fig.3. 1 A diagram showing the process for interpreting each design guideline in order to gather information suitable for programming.

- 99 detailed manufacturing guidelines to be translated for software programming

- 4 domains considered within the manufacturing process;

- Tooling

- Process Planning

- Material

- Geometry

Reasons were provided for why each design guideline should be used as it was felt this would help

provide further guidance for the user during the use of the software and provide useful hints which

they can take into account in further product development and therefore help improve their overall

detailed design-ability.

Many of the Design for Manufacture Guidelines identified had to be listed more than once, due to the

nature of the design guideline and its ability to be used to provide details for more than one

component feature. As 4 main manufacturing domains, as listed above, had been identified this also

added to the complexity when interpreting the design guidelines.

5. Discussion Once the output from the initial findings had been analysed, many challenges were highlighted which

allowed issues within the research to be addressed to allow further progression towards developing

the software analysis tool;

One of the main challenges was access to good, trustworthy resources. Design for Manufacture

Guidelines have always been vague in nature and open to interpretation from the designer. Although

there are a large number of resources stating hundreds of different design guidelines very few of them

assign specific values for various features which may be applied to any component. To overcome this

issue experience in manufacturing and using these design guidelines were necessary.

While completing the required conditional, value and limitation components during the guideline

interpretation, it became apparent that some of the design guidelines listed would have to be further

defined in terms of the material type being used for the manufacture of the component. The type of

material plays a particularly important role within the design of the component. Different materials

require different cutting speeds, different minimum material thicknesses, various surface finish

requirement and many more important variable tolerances which ultimately affect and change the

design of a component.

The requirement to produce up to 5 mapping tables was established upon completing the initial

database of interpreted Design for Manufacture Guidelines. This was mainly due to a programming

requirement to ensure flexibility of the operating system.

5.1 Future Developments On completion of the project after 11 weeks there were four key areas identified for future

progression and development of the software analysis tool;

Testing and analysis of milling guidelines within the tool. The research produced many more guidelines

than initially intended and the issues highlighted in the discussion section had to be resolved, this left

no time within this project for testing and analysis.

The incorporation of Design for Manufacture Guidelines for other manufacturing processes. The aim

is to include every manufacturing process within the analysis tool in order to automate the design

optimization process for components and to make life easier for the designer.

Testing of the interface may be required to ensure the designer is able to understand and navigate

around the tool with ease. The tool must be easy to use with no ambiguity in meaning as these are

the current problems with the design guidelines which this tool aims to address.

The development of the tool into a commercially available programme with possible incorporation in

computer product modelling software tools such as ProEngineer and Solidworks.

Fig.5. 1 A diagram showing the further definition of each design guideline to help produce mapping tables to help the programming process.

6. Conclusion The aim of this project was to develop a fundamental piece of software based on the design for

manufacture guidelines and principals which could help to reduce time in the development and

manufacturing phase involved in product development. It was hoped that a comprehensive software-

based package would be produced as a result of the outcome of this research, enabling the user to

import a 3D model of a component into a compatible package and undertake an analysis of the

component, with a specific focus on component features in relation to their suitability of use within

the context of the manufacturing process.

At the end of this project, most of the objectives and aims defined at the outset have been achieved.

There is now a comprehensive list of Design for Manufacture guidelines relating to the milling process

and the process for placing this information into a software programming format is currently taking

place. There were some challenges throughout the duration of the project and these have been

discussed and overcome as necessary. However due to some of these issues, the testing and analysis

phase of the project was not completed within the project time-frame. The plan is to continue with

work on the project to complete this phase in order to produce a prototype of a possible software

analysis tool.

Fig.5.1. 1 An image illustrating the software user interface showing the 3D component which will be used for testing.

6.1 Project Reflection In the three month internship, I have gained a wider knowledge base and skills than I expected

especially relating to the complexities associated with developing software. The requirement for the

project was a solid background knowledge of the use of Design for Manufacture guidelines and criteria

for use and I felt I could easily apply the experience and knowledge I had gained from many classes

during the course of my undergraduate degree. The main output of the project, developing an

intelligent, reason-based software analysis tool which could analyse and optimise 3D components

automatically sounded daunting at first but I have been given an opportunity to consolidate, apply

and expand the knowledge which I brought with me from class-based learning.

Although the project was not fully completed due to complex issues with programming and how to

interpret the gathered information into useable programme code, I feel I have gained a lot from this

experience. I have not only built on my design for manufacture guideline knowledge but I now also

have an insight into how different professions can collaborate on a project, utilising independent skills

to help produce one working outcome, it has been an interesting experience to see how my knowledge

can be adapted by a computer scientist in order to produce a tool which can benefit not only business

in its industry application, but also students and the potential the tool has to improve the product

development process.

Having the opportunity to meet with other students, many of whom were postgraduate students

completing their dissertation, provided me with some very useful knowledge, it was a good

opportunity to speak to them and find out about their work and interests and what some of their

experiences had been while completing their dissertation work. Furthermore the chance to become

part of the Undergraduate Research Community within Strathclyde was a bonus to the internship, it

provided the ability to discuss and share so challenges and problems which may have been occurring,

or sharing different project experiences good and bad, this was also a one-off chance to meet with

many other students from across the university regardless of what department or faculty they were

from. This was a great experience as this rarely happens within the normal student life of the

university. Overall the project has provided me with confidence and a stepping-stone on which I can

build my dissertation as I plan to complete the project to fulfil the dissertation criteria. Throughout

the project I have met many different people, worked in a different environment from what I am used

to as an undergraduate student, and I have learnt a lot from every experience during this project. I

look forward to utilising this further within my dissertation and long into the future.

References [1] Millar, L.T., (2013), ‘The Cost-Reduction-Consultant: Importance of Cost Reduction’, available at

http://www.the-cost-reduction-consultant.com/ImportanceOfCostReduction.html, accessed 05

August 2013

[2] Boothroyd, G., P. Dewhurst, W. A. Knight (2002) Product Design for Manufacture and Assembly,

Madison Avenue, NY: Marcel Dekker, Inc.

[3] Rembold, U., B. O. Nnaji and A. Storr (1993), Computer Integrated Manufacturing and Engineering,

Wokingham, England: Addison-Wesley Pub. Co