DM306 Week 8.pptx
Transcript
DM306 Week 8 Vicky Hamilton [email protected] Programme 1pm-1.15pm – Paul, Design Hopes 1.15pm-1.35pm – DFMA Lecture 1.35pm-2.05pm – DFMA dismantle activity 2.05pm-2.15pm – Break 2.15pm-2.40pm – VA/VE Lecture 2.40pm-3pm – VA/VE Activity 3pm-4pm – Group Work Part 1: DFMA What is DFMA? DF...
DM306 Week 8 Vicky Hamilton [email protected] Programme 1pm-1.15pm – Paul, Design Hopes 1.15pm-1.35pm – DFMA Lecture 1.35pm-2.05pm – DFMA dismantle activity 2.05pm-2.15pm – Break 2.15pm-2.40pm – VA/VE Lecture 2.40pm-3pm – VA/VE Activity 3pm-4pm – Group Work Part 1: DFMA What is DFMA? DFMA is a way of thinking that strives to make manufacture & assembly easier and quicker without compromising on quality or functionality of the product; which ultimately leads to cost savings DFMA is a product of the automation endeavours of the late 70’s & early 80’s Assembly is the biggest consumer of labour in manufacturing. Widely adopted approach of many manufacturers – Optimise material costs – Optimise manufacturing processes – Minimise the complexity of product solutions – Reduce time to market Today DFMA is well recognised as a component of Lean Manufacturing Put simply, DFMA is a way of thinking that aims to optimise the design at an early stage to consider it’s future manufacture and assembly The need for DFMA 75-85% of overall product cost is committed during the design and planning stage Considering DFMA at an early stage has the potential to eliminate 20-30% of assembly costs Significant cost saving opportunity Costs: People Costs: Prototyp es Costs: Tooling Cost Committed 100 % 80 % Cost Incurred 66 % Ease of Change NEED CONTRIBUTION Costs: Maintenanc e Concep t Design Detaile d Design Constructio n System Use DFMA Benefits Supports the adoption of concurrent engineering Provides guidance to design teams to help them: simplify product structures reduce manufacturing and assembly costs increase productivity quantify improvements. Highlights deficiencies in existing product designs with respect to automation capability. Benefits also apply to manual assembly Key issues Interactions between product and manufacturing process should be understood and considered. Design decisions have an associated cost. Product and manufacturing decisions must be made in parallel. The product design must be carefully matched to: – advanced flexible manufacturing – assembly – quality control – material-handling DFMA approaches It is convenient to divide the subject of DFMA in two considerations a) Organisational and Management Issues b) Methods and Tools a) Organisational and Management Issues b) Methods and Tools DFMA supports Concurrent Engineering Use appropriate methods and tools Requires the integration of diverse and complex Costs associated with method information, so Consider organisation & management implementation structure Consider communication issues Training in guidelines & general awareness DFMA Methods & Tools DFMA methods DFMA Guidelines All encompassing rules/principles for best practice for economic manufacture and assembly. DFMA Systematic Methodical techniques based upon workbooks or Evaluation Methods software. Value Analysis and Cost reduction without compromising value to the Engineering customer through function definition and function-cost analysis. 1. DFMA Guidelines All encompassing rules/principles for best practice for economic manufacture and assembly. 1. DFMA Guidelines 1. Minimise & optimise handling 2. Maximise part symmetry 3. Minimise assembly directions 4. Design parts for ease of fabrication 5. Design integral self locking features 6. Minimise the total number of parts 7. Use of modular design 8. Standardisation of components 9. Minimisation of variation 10. Design parts to be multifunctional DFMA Guidelines - Examples Guideline Minimise parts variation Design integral selflocking features Minimise total number of parts Original Design Redesign Summary Ensuring strong understanding will: – Improve product designs at an early stage – Ensure ease of manufacture – Save time and money 2. DFMA Systematic Evaluation Methods Systematic Evaluation is a methodical approach to evaluating a design against set standards or criteria and identifying its worth and significance. Assemblability Evaluation Method Lucas Method Boothroyd & Dewhurst Method Methodical techniques based upon workbooks or software Assemblability Evaluation Method Preparation Developed in 1975 by Hitachi Ltd Aim to improve design quality for better assembly Calculation of 3 values: P – Suitability of assembly individual parts E – Overall assembly suitability K – Estimated assembly-cost ratio Provides quantitative values Stipulate Assembly Sequence Stipulate Assembly Techniques Calculate Evaluation Values Appraise the Evaluation Values Lucas Method Specification Method developed in early 1980’s by The Lucas Corp Design Calculation of four values: Functional Analysis – parts reviewed for their function Functional Analysis Feeding Analysis – analysis of handling and insertion times Fitting Analysis – analysis of part fittings Manufacturing Analysis – cost analysis of each component Feeding Analysis Fitting Analysis based on material and manufacturing process Provides quantitative values Manufacturing Analysis Assessment Boothroyd & Dewhurst Method Method developed in the 1980’s Aim to reduce amount of assembly required for existing products Calculates: Time to assemble Overall design efficiency Provides quantitative values Systematic Evaluation Methods: Provide quantifiable values and results Allow designers to compare designs with future assembly and manufacturability in mind Systematic in approach (follow a process for evaluation) Follow the principles of the DFMA guidelines Historically ‘workbooks’ more currently ‘software’ https://www.youtube.com/embed/E7_afjJTAok?rel=0&showinfo=0&autopl ay=1 3. Value Analysis & Value Engineering Aim: increase or maintain the value of a product to the customer. reducing the cost to its producer. Maintaining quality and reliability of a design. Identifying & removing unnecessary costs. Not the same as cost reduction Summary DFMA guidelines can aid a designer throughout the design process There are a number of DFMA methods that be adopted to implanted DFMA within your organisation Ultimately a strong understanding of DFMA basic principles will result in better designed products from a manufacturing perspective which present cost saving opportunities A couple of thoughts from my experience on the importance of DFMA Manufacturing Process Selection: Make sure you consider ALL applicable manufacturing processes – don’t just jump in to the most obvious e.g. injection moulding Different processes will drive different design decisions Your decisions drive significant cost EXAMPLE: Recoil Gaiter – injection moulded but dip moulding probably a better choice. Injection Moulding Dip Moulding Will produce the part Will produce the part Undercuts - Manual removal from mould required Undercuts - Manual removal from mould required Only 1 part produced each cycle Multiple parts produced each cycle 1 Mould cost around £4,500 1 Mould cost around £550 Design Decision Impact: Need for two gates for injection moulding – thoughts on where these would be located No gates needed Shape restrictions Less shape restrictions A couple of thoughts from my experience on the importance of DFMA Assess each part against each guideline – just because you can, doesn’t always mean you should. Guideline 6: Minimise the total number of parts – good because, combining parts potentially reduces assembly time, however will combing parts increase manufacture cost? EXAMPLE: Recoil Floor Contact & Floor Protector Two parts bonded with tape provided by 3M Floor Contact – Unit cost £1.50 Floor Protector – Unit cost £1 Apply 3M tape to Floor Protector and leave for 24 hrs – Tape unit cost £0.90 Manually apply floor protector to floor contact - Operator time 30 seconds (£0.07) Overmoulded Floor Contact HOWEVER can increase manufacturing costs Change to component design Will need to be features on floor contact to support overmould Increased cycle time More complex mould – increased mould cost Why are we doing todays activity? DFMA guidelines are very practical pieces of knowledge Much easier to understand application when you can see physical examples of them being applied in practice Part 1 - Activity DFMA dismantle and discover exercise Dismantle one of your brought in products Analyse the DFMA features and identify: ‘best features’ of DFMA in an existing product design ‘worst features’ of DFMA (if there are any) Suggest ways to improve the product Couple of other DFMA thoughs… Redesigns are costly: Average product design consultancy charges £400-£600 per day, a stage like concept generation could be average 5 days work Manufacturing Mould changes are costly: Recoil Logo: £750 Disconnect mould from machine – production downtime Transport of mould – time and sustainability impacts Trailling of mould on return – time and risks of issues Additional hidden lesson…..don’t forget about branding… Summary – mistakes or poor decisions cost money, which in start-up world can be difference between product success and product failure. Break Value Analysis (VA) & Value Engineering (VE) V a l u e A n a l y Value Analysis tends to refer to the detailed analysis of components in existing products. Involves looking at functionality with the aim of reducing unnecessary cost while maintaining high value features/functions Value Engineering is broader in scope and tends to focus on new designs or the substantial redesign of a product. Involves looking at the high valued functions with the aim of enhancing them without adding cost VA & VE Identifying & removing unnecessary costs. Maintaining quality and reliability of a design. To increase or maintain the value of a product to its purchaser whilst reducing the cost to its producer. The more highly valued features or functions should account for the highest proportion of product cost. Not the same as cost reduction Cost vs. value Cost relates to how much effort is required to obtain a particular commodity. Value is dependent on the circumstances in which it is used Example: – The cost to manufacture a Lamborghini – How much customers value owning a Lamborghini VA vs. VE Value Analysis tends to refer to the detailed analysis of components in existing products. Involves looking at functionality with the aim of reducing unnecessary cost – Hole punch Identify what the customer values Look to minimise or reduce cost of components associated with lowest valued function VA vs. VE Value Engineering is broader in scope and tends to focus on new designs or the substantial redesign of a product. Involves looking at the high valued functions with the aim of enhancing them – Torch body Improve battery storage Stability when put down Easy to carry – Reflector & bulb Redirecting beam Energy efficient light bulb Information needs Customer value for each function/feature Component costs Stock control & financial reports Manufacturing & assembly costs Market research Process & value stream mapping Effective communication Summary VA & VE are DFMA methods Aim: increase or maintain the value of a product to the customer. reducing the cost to its producer. Not the same as cost reduction. Requires information in relation to: – Value of functions as perceived by customers. – Detailed component & assembly cost. Teamwork and effective communication are crucial to this method Steps in conducting Value Analysis (VA) & Value Engineering (VE) 1. Strip down product 2. Identify functions 3. Determine value of function 6. Evaluate alternatives and select improvements 5. Reduce cost without reducing value or add value without adding cost 4. Determine cost of components Breakdown 1. Stripping down a product: – Use exploded drawings and itemised component lists – Literally and physically Component Cap Washer Glass Reflector Bulb Bulb holder Torch body Switch Spring Washer Cap Loop Component Function What does this do? 2. Identify the function of each component – Function analysis – Product understanding Cap Washer Glass Protect bulb and reflector Reflector Bulb Bulb holder Project light beam Provide light Hold bulb, provide electrical contact Torch body Contain batteries, locate parts, provide hand grip Switch Spring Washer Provide electrical interrupt Provide pressure on batteries Cap Loop Protect batteries Provide for hanging The true value of functions 3. Determine the value of the identified functions – Through Market Research – Value as perceived by the customer Component Function Value Cap Washer Glass Protect bulb and reflector Medium Reflector Project light beam High Bulb Provide light High Bulb holder Hold bulb, provide electrical contact Low Torch body Contain batteries, locate parts, provide hand grip High Switch Provide electrical interrupt High Spring Washer Provide pressure on batteries Low Cap Protect batteries Medium Loop Provide for hanging Low TOTAL The real cost of components 4. Determine the cost of the components – Full costing for each component: Not the same as manufacturing cost or purchase price Includes all processing, handling, assembly costs Cost(£) Component Function Value Cap Washer Glass Protect bulb and reflector Medium 0.16 Reflector Project light beam High 0.12 Bulb Provide light High 0.10 Bulb holder Hold bulb, provide electrical contact Contain batteries, locate parts, provide hand grip Low 0.05 High 0.26 Switch Provide electrical interrupt High 0.08 Spring Washer Provide pressure on batteries Low 0.10 Cap Protect batteries Medium 0.10 Loop Provide for hanging Low 0.03 Torch body TOTAL Original £1.00 Analytical & creative methods 5. Identify ways of reducing cost without reducing value or adding value without adding cost – – Need to be both critical and creative: Cost(£) Componen t Cap Washer Glass Function Value Original Redesig n 0.16 0.08 Protect bulb and reflector Mediu m Reflector Project light beam High 0.12 0.12 Bulb Provide light High 0.10 0.10 Bulb holder Hold bulb, provide electrical contact Contain batteries, locate parts, provide hand grip Low 0.05 0.05 High 0.26 0.26 0.08 Critical looks at what the design is Torch body Creative looks at what the design might Switch Provide electrical interrupt High 0.08 be Spring Washer Provide pressure on batteries Low 0.10 Cap Protect batteries 0.10 Provide for hanging Mediu m Low Guidelines available: Cost reduction – Value Analysis Loop Value attributes - Value Engineering TOTAL 0.10 0.03 - £1.00 £0.79 Cost Reduction Guidelines Reduce cost without reducing value Eliminate: Can any function and it’s components be eliminated? Are there redundant components. Reduce: Can the number of components be reduced? Can components be combined? Simplify : Is there a simpler alternative? Is there an easier assembly sequence? Is there a simpler shape? Modify: Can cheaper material be used? Can the manufacturing method be improved? Standardise: Can standard parts be used? Can dimensions be standardised? Cost Reduction Guidelines Example Eliminate Function Value Cap Washer Glass Protect bulb and reflector Mediu m 0.16 0.08 Reflector Project light beam High 0.12 0.12 Bulb Provide light High 0.10 0.10 Bulb holder Hold bulb, provide electrical contact Contain batteries, locate parts, provide hand grip Low 0.05 0.05 High 0.26 0.26 Switch Provide electrical interrupt High 0.08 0.08 Spring Washer Provide pressure on batteries Low 0.10 washer with cap Cap Protect batteries 0.10 Eliminate: Eliminate Loop Loop Provide for hanging Mediu m Low Reduce Simplify Cost(£) Componen t £0.21 Saving per unit Modify Standardise Reduce: Combine spring Simplify: Cap Washer Glass Torch body TOTAL Original Redesig n 0.10 0.03 - £1.00 £0.79 Value Attributes Guidelines Increase value without increasing cost Utility: Performance on aspects such as capacity, power, speed, accuracy or versatility. User friendly: Easy to use, transport and intuitive design. Reliability: Freedom from breakdown or malfunction in particular environments. Safety: Secure, hazard-free operation. Maintenance: Simple, infrequent or maintenance free. Lifetime: Extended product lifetime. VE Example Lifetime: Extended bulb lifetime. User Friendly: Improve ergonomics Cost(£) Componen t Cap Washer Glass Function Value Protect bulb and reflector Mediu m Reflector Project light beam High 0.12 0.12 Bulb Provide light High 0.10 0.10 Bulb holder Hold bulb, provide electrical contact Low 0.05 0.05 Torch body Contain batteries, locate parts, provide hand grip High 0.26 Switch Provide electrical interrupt High 0.08 Spring Washer Cap Provide pressure on batteries Low 0.10 Loop TOTAL Protect batteries Provide for hanging Mediu m Low Original Redesig n 0.16 0.08 0.10 £0.21 Saving per unit & deliver more value! Utility User friendly 0.26 Reliability 0.08 Safety Maintenance Lifetime 0.10 0.03 - £1.00 £0.79 Evaluation 6. Evaluate alternatives and select improvements: – Value analysis or value engineering should result in a number of alternative suggestions in the design. – Some may be conflicting therefore thorough analysis of all changes should be undertaken. – Only suggestions which are genuine improvements should be implemented. V A A c t i v i t y Value Analysis tends to refer to the detailed analysis of components in existing products. Involves looking at functionality with the aim of reducing unnecessary cost Part 2 - Activity Conduct a VA on the hole punch State what changes you might consider making to the punch to improve its value to the customer Also state any assumptions that you make about the market or manufacturing process. V A S o l u t i o n 65% of the cost of punch is concerned with the most important function, ‘punch hole’ The handle lock mechanism receives a low importance rating from customer Is it necessary? Can we use an alternative?
